1/*
2 * NetLabel System
3 *
4 * The NetLabel system manages static and dynamic label mappings for network
5 * protocols such as CIPSO and RIPSO.
6 *
7 * Author: Paul Moore <paul@paul-moore.com>
8 *
9 */
10
11/*
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
13 *
14 * This program is free software;  you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
22 * the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program;  if not, see <http://www.gnu.org/licenses/>.
26 *
27 */
28
29#ifndef _NETLABEL_H
30#define _NETLABEL_H
31
32#include <linux/types.h>
33#include <linux/slab.h>
34#include <linux/net.h>
35#include <linux/skbuff.h>
36#include <linux/in.h>
37#include <linux/in6.h>
38#include <net/netlink.h>
39#include <net/request_sock.h>
40#include <linux/atomic.h>
41
42struct cipso_v4_doi;
43
44/*
45 * NetLabel - A management interface for maintaining network packet label
46 *            mapping tables for explicit packet labling protocols.
47 *
48 * Network protocols such as CIPSO and RIPSO require a label translation layer
49 * to convert the label on the packet into something meaningful on the host
50 * machine.  In the current Linux implementation these mapping tables live
51 * inside the kernel; NetLabel provides a mechanism for user space applications
52 * to manage these mapping tables.
53 *
54 * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
55 * send messages between kernel and user space.  The general format of a
56 * NetLabel message is shown below:
57 *
58 *  +-----------------+-------------------+--------- --- -- -
59 *  | struct nlmsghdr | struct genlmsghdr | payload
60 *  +-----------------+-------------------+--------- --- -- -
61 *
62 * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
63 * The payload is dependent on the subsystem specified in the
64 * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
65 * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
66 * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
67 * the include/net/netlink.h file for more information on NETLINK attributes.
68 *
69 */
70
71/*
72 * NetLabel NETLINK protocol
73 */
74
75/* NetLabel NETLINK protocol version
76 *  1: initial version
77 *  2: added static labels for unlabeled connections
78 *  3: network selectors added to the NetLabel/LSM domain mapping and the
79 *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
80 */
81#define NETLBL_PROTO_VERSION            3
82
83/* NetLabel NETLINK types/families */
84#define NETLBL_NLTYPE_NONE              0
85#define NETLBL_NLTYPE_MGMT              1
86#define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
87#define NETLBL_NLTYPE_RIPSO             2
88#define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
89#define NETLBL_NLTYPE_CIPSOV4           3
90#define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
91#define NETLBL_NLTYPE_CIPSOV6           4
92#define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
93#define NETLBL_NLTYPE_UNLABELED         5
94#define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
95#define NETLBL_NLTYPE_ADDRSELECT        6
96#define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
97
98/*
99 * NetLabel - Kernel API for accessing the network packet label mappings.
100 *
101 * The following functions are provided for use by other kernel modules,
102 * specifically kernel LSM modules, to provide a consistent, transparent API
103 * for dealing with explicit packet labeling protocols such as CIPSO and
104 * RIPSO.  The functions defined here are implemented in the
105 * net/netlabel/netlabel_kapi.c file.
106 *
107 */
108
109/* NetLabel audit information */
110struct netlbl_audit {
111	u32 secid;
112	kuid_t loginuid;
113	unsigned int sessionid;
114};
115
116/*
117 * LSM security attributes
118 */
119
120/**
121 * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
122 * @refcount: atomic reference counter
123 * @free: LSM supplied function to free the cache data
124 * @data: LSM supplied cache data
125 *
126 * Description:
127 * This structure is provided for LSMs which wish to make use of the NetLabel
128 * caching mechanism to store LSM specific data/attributes in the NetLabel
129 * cache.  If the LSM has to perform a lot of translation from the NetLabel
130 * security attributes into it's own internal representation then the cache
131 * mechanism can provide a way to eliminate some or all of that translation
132 * overhead on a cache hit.
133 *
134 */
135struct netlbl_lsm_cache {
136	atomic_t refcount;
137	void (*free) (const void *data);
138	void *data;
139};
140
141/**
142 * struct netlbl_lsm_catmap - NetLabel LSM secattr category bitmap
143 * @startbit: the value of the lowest order bit in the bitmap
144 * @bitmap: the category bitmap
145 * @next: pointer to the next bitmap "node" or NULL
146 *
147 * Description:
148 * This structure is used to represent category bitmaps.  Due to the large
149 * number of categories supported by most labeling protocols it is not
150 * practical to transfer a full bitmap internally so NetLabel adopts a sparse
151 * bitmap structure modeled after SELinux's ebitmap structure.
152 * The catmap bitmap field MUST be a power of two in length and large
153 * enough to hold at least 240 bits.  Special care (i.e. check the code!)
154 * should be used when changing these values as the LSM implementation
155 * probably has functions which rely on the sizes of these types to speed
156 * processing.
157 *
158 */
159#define NETLBL_CATMAP_MAPTYPE           u64
160#define NETLBL_CATMAP_MAPCNT            4
161#define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
162#define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
163					 NETLBL_CATMAP_MAPCNT)
164#define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
165struct netlbl_lsm_catmap {
166	u32 startbit;
167	NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
168	struct netlbl_lsm_catmap *next;
169};
170
171/**
172 * struct netlbl_lsm_secattr - NetLabel LSM security attributes
173 * @flags: indicate structure attributes, see NETLBL_SECATTR_*
174 * @type: indicate the NLTYPE of the attributes
175 * @domain: the NetLabel LSM domain
176 * @cache: NetLabel LSM specific cache
177 * @attr.mls: MLS sensitivity label
178 * @attr.mls.cat: MLS category bitmap
179 * @attr.mls.lvl: MLS sensitivity level
180 * @attr.secid: LSM specific secid token
181 *
182 * Description:
183 * This structure is used to pass security attributes between NetLabel and the
184 * LSM modules.  The flags field is used to specify which fields within the
185 * struct are valid and valid values can be created by bitwise OR'ing the
186 * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
187 * specify domain specific configuration settings and is not usually used by
188 * NetLabel itself when returning security attributes to the LSM.
189 *
190 */
191struct netlbl_lsm_secattr {
192	u32 flags;
193	/* bitmap values for 'flags' */
194#define NETLBL_SECATTR_NONE             0x00000000
195#define NETLBL_SECATTR_DOMAIN           0x00000001
196#define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
197					 NETLBL_SECATTR_FREE_DOMAIN)
198#define NETLBL_SECATTR_CACHE            0x00000002
199#define NETLBL_SECATTR_MLS_LVL          0x00000004
200#define NETLBL_SECATTR_MLS_CAT          0x00000008
201#define NETLBL_SECATTR_SECID            0x00000010
202	/* bitmap meta-values for 'flags' */
203#define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
204#define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
205					 NETLBL_SECATTR_MLS_CAT | \
206					 NETLBL_SECATTR_SECID)
207	u32 type;
208	char *domain;
209	struct netlbl_lsm_cache *cache;
210	struct {
211		struct {
212			struct netlbl_lsm_catmap *cat;
213			u32 lvl;
214		} mls;
215		u32 secid;
216	} attr;
217};
218
219/*
220 * LSM security attribute operations (inline)
221 */
222
223/**
224 * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
225 * @flags: the memory allocation flags
226 *
227 * Description:
228 * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
229 * on success, NULL on failure.
230 *
231 */
232static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
233{
234	struct netlbl_lsm_cache *cache;
235
236	cache = kzalloc(sizeof(*cache), flags);
237	if (cache)
238		atomic_set(&cache->refcount, 1);
239	return cache;
240}
241
242/**
243 * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
244 * @cache: the struct to free
245 *
246 * Description:
247 * Frees @secattr including all of the internal buffers.
248 *
249 */
250static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
251{
252	if (!atomic_dec_and_test(&cache->refcount))
253		return;
254
255	if (cache->free)
256		cache->free(cache->data);
257	kfree(cache);
258}
259
260/**
261 * netlbl_catmap_alloc - Allocate a LSM secattr catmap
262 * @flags: memory allocation flags
263 *
264 * Description:
265 * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
266 * on failure.
267 *
268 */
269static inline struct netlbl_lsm_catmap *netlbl_catmap_alloc(gfp_t flags)
270{
271	return kzalloc(sizeof(struct netlbl_lsm_catmap), flags);
272}
273
274/**
275 * netlbl_catmap_free - Free a LSM secattr catmap
276 * @catmap: the category bitmap
277 *
278 * Description:
279 * Free a LSM secattr catmap.
280 *
281 */
282static inline void netlbl_catmap_free(struct netlbl_lsm_catmap *catmap)
283{
284	struct netlbl_lsm_catmap *iter;
285
286	while (catmap) {
287		iter = catmap;
288		catmap = catmap->next;
289		kfree(iter);
290	}
291}
292
293/**
294 * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
295 * @secattr: the struct to initialize
296 *
297 * Description:
298 * Initialize an already allocated netlbl_lsm_secattr struct.
299 *
300 */
301static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
302{
303	memset(secattr, 0, sizeof(*secattr));
304}
305
306/**
307 * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
308 * @secattr: the struct to clear
309 *
310 * Description:
311 * Destroys the @secattr struct, including freeing all of the internal buffers.
312 * The struct must be reset with a call to netlbl_secattr_init() before reuse.
313 *
314 */
315static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
316{
317	if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
318		kfree(secattr->domain);
319	if (secattr->flags & NETLBL_SECATTR_CACHE)
320		netlbl_secattr_cache_free(secattr->cache);
321	if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
322		netlbl_catmap_free(secattr->attr.mls.cat);
323}
324
325/**
326 * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
327 * @flags: the memory allocation flags
328 *
329 * Description:
330 * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
331 * pointer on success, or NULL on failure.
332 *
333 */
334static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
335{
336	return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
337}
338
339/**
340 * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
341 * @secattr: the struct to free
342 *
343 * Description:
344 * Frees @secattr including all of the internal buffers.
345 *
346 */
347static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
348{
349	netlbl_secattr_destroy(secattr);
350	kfree(secattr);
351}
352
353#ifdef CONFIG_NETLABEL
354/*
355 * LSM configuration operations
356 */
357int netlbl_cfg_map_del(const char *domain,
358		       u16 family,
359		       const void *addr,
360		       const void *mask,
361		       struct netlbl_audit *audit_info);
362int netlbl_cfg_unlbl_map_add(const char *domain,
363			     u16 family,
364			     const void *addr,
365			     const void *mask,
366			     struct netlbl_audit *audit_info);
367int netlbl_cfg_unlbl_static_add(struct net *net,
368				const char *dev_name,
369				const void *addr,
370				const void *mask,
371				u16 family,
372				u32 secid,
373				struct netlbl_audit *audit_info);
374int netlbl_cfg_unlbl_static_del(struct net *net,
375				const char *dev_name,
376				const void *addr,
377				const void *mask,
378				u16 family,
379				struct netlbl_audit *audit_info);
380int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
381			   struct netlbl_audit *audit_info);
382void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info);
383int netlbl_cfg_cipsov4_map_add(u32 doi,
384			       const char *domain,
385			       const struct in_addr *addr,
386			       const struct in_addr *mask,
387			       struct netlbl_audit *audit_info);
388/*
389 * LSM security attribute operations
390 */
391int netlbl_catmap_walk(struct netlbl_lsm_catmap *catmap, u32 offset);
392int netlbl_catmap_walkrng(struct netlbl_lsm_catmap *catmap, u32 offset);
393int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
394			  u32 *offset,
395			  unsigned long *bitmap);
396int netlbl_catmap_setbit(struct netlbl_lsm_catmap **catmap,
397			 u32 bit,
398			 gfp_t flags);
399int netlbl_catmap_setrng(struct netlbl_lsm_catmap **catmap,
400			 u32 start,
401			 u32 end,
402			 gfp_t flags);
403int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
404			  u32 offset,
405			  unsigned long bitmap,
406			  gfp_t flags);
407
408/*
409 * LSM protocol operations (NetLabel LSM/kernel API)
410 */
411int netlbl_enabled(void);
412int netlbl_sock_setattr(struct sock *sk,
413			u16 family,
414			const struct netlbl_lsm_secattr *secattr);
415void netlbl_sock_delattr(struct sock *sk);
416int netlbl_sock_getattr(struct sock *sk,
417			struct netlbl_lsm_secattr *secattr);
418int netlbl_conn_setattr(struct sock *sk,
419			struct sockaddr *addr,
420			const struct netlbl_lsm_secattr *secattr);
421int netlbl_req_setattr(struct request_sock *req,
422		       const struct netlbl_lsm_secattr *secattr);
423void netlbl_req_delattr(struct request_sock *req);
424int netlbl_skbuff_setattr(struct sk_buff *skb,
425			  u16 family,
426			  const struct netlbl_lsm_secattr *secattr);
427int netlbl_skbuff_getattr(const struct sk_buff *skb,
428			  u16 family,
429			  struct netlbl_lsm_secattr *secattr);
430void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
431
432/*
433 * LSM label mapping cache operations
434 */
435void netlbl_cache_invalidate(void);
436int netlbl_cache_add(const struct sk_buff *skb,
437		     const struct netlbl_lsm_secattr *secattr);
438
439/*
440 * Protocol engine operations
441 */
442struct audit_buffer *netlbl_audit_start(int type,
443					struct netlbl_audit *audit_info);
444#else
445static inline int netlbl_cfg_map_del(const char *domain,
446				     u16 family,
447				     const void *addr,
448				     const void *mask,
449				     struct netlbl_audit *audit_info)
450{
451	return -ENOSYS;
452}
453static inline int netlbl_cfg_unlbl_map_add(const char *domain,
454					   u16 family,
455					   void *addr,
456					   void *mask,
457					   struct netlbl_audit *audit_info)
458{
459	return -ENOSYS;
460}
461static inline int netlbl_cfg_unlbl_static_add(struct net *net,
462					      const char *dev_name,
463					      const void *addr,
464					      const void *mask,
465					      u16 family,
466					      u32 secid,
467					      struct netlbl_audit *audit_info)
468{
469	return -ENOSYS;
470}
471static inline int netlbl_cfg_unlbl_static_del(struct net *net,
472					      const char *dev_name,
473					      const void *addr,
474					      const void *mask,
475					      u16 family,
476					      struct netlbl_audit *audit_info)
477{
478	return -ENOSYS;
479}
480static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
481					 struct netlbl_audit *audit_info)
482{
483	return -ENOSYS;
484}
485static inline void netlbl_cfg_cipsov4_del(u32 doi,
486					  struct netlbl_audit *audit_info)
487{
488	return;
489}
490static inline int netlbl_cfg_cipsov4_map_add(u32 doi,
491					     const char *domain,
492					     const struct in_addr *addr,
493					     const struct in_addr *mask,
494					     struct netlbl_audit *audit_info)
495{
496	return -ENOSYS;
497}
498static inline int netlbl_catmap_walk(struct netlbl_lsm_catmap *catmap,
499				     u32 offset)
500{
501	return -ENOENT;
502}
503static inline int netlbl_catmap_walkrng(struct netlbl_lsm_catmap *catmap,
504					u32 offset)
505{
506	return -ENOENT;
507}
508static inline int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
509					u32 *offset,
510					unsigned long *bitmap)
511{
512	return 0;
513}
514static inline int netlbl_catmap_setbit(struct netlbl_lsm_catmap **catmap,
515				       u32 bit,
516				       gfp_t flags)
517{
518	return 0;
519}
520static inline int netlbl_catmap_setrng(struct netlbl_lsm_catmap **catmap,
521				       u32 start,
522				       u32 end,
523				       gfp_t flags)
524{
525	return 0;
526}
527static inline int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
528					u32 offset,
529					unsigned long bitmap,
530					gfp_t flags)
531{
532	return 0;
533}
534static inline int netlbl_enabled(void)
535{
536	return 0;
537}
538static inline int netlbl_sock_setattr(struct sock *sk,
539				      u16 family,
540				      const struct netlbl_lsm_secattr *secattr)
541{
542	return -ENOSYS;
543}
544static inline void netlbl_sock_delattr(struct sock *sk)
545{
546}
547static inline int netlbl_sock_getattr(struct sock *sk,
548				      struct netlbl_lsm_secattr *secattr)
549{
550	return -ENOSYS;
551}
552static inline int netlbl_conn_setattr(struct sock *sk,
553				      struct sockaddr *addr,
554				      const struct netlbl_lsm_secattr *secattr)
555{
556	return -ENOSYS;
557}
558static inline int netlbl_req_setattr(struct request_sock *req,
559				     const struct netlbl_lsm_secattr *secattr)
560{
561	return -ENOSYS;
562}
563static inline void netlbl_req_delattr(struct request_sock *req)
564{
565	return;
566}
567static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
568				      u16 family,
569				      const struct netlbl_lsm_secattr *secattr)
570{
571	return -ENOSYS;
572}
573static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
574					u16 family,
575					struct netlbl_lsm_secattr *secattr)
576{
577	return -ENOSYS;
578}
579static inline void netlbl_skbuff_err(struct sk_buff *skb,
580				     int error,
581				     int gateway)
582{
583	return;
584}
585static inline void netlbl_cache_invalidate(void)
586{
587	return;
588}
589static inline int netlbl_cache_add(const struct sk_buff *skb,
590				   const struct netlbl_lsm_secattr *secattr)
591{
592	return 0;
593}
594static inline struct audit_buffer *netlbl_audit_start(int type,
595						struct netlbl_audit *audit_info)
596{
597	return NULL;
598}
599#endif /* CONFIG_NETLABEL */
600
601#endif /* _NETLABEL_H */
602