xref: /linux/include/net/netlabel.h (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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.moore@hp.com>
8  *
9  */
10 
11 /*
12  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
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, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27  *
28  */
29 
30 #ifndef _NETLABEL_H
31 #define _NETLABEL_H
32 
33 #include <linux/types.h>
34 #include <linux/net.h>
35 #include <linux/skbuff.h>
36 #include <net/netlink.h>
37 #include <asm/atomic.h>
38 
39 /*
40  * NetLabel - A management interface for maintaining network packet label
41  *            mapping tables for explicit packet labling protocols.
42  *
43  * Network protocols such as CIPSO and RIPSO require a label translation layer
44  * to convert the label on the packet into something meaningful on the host
45  * machine.  In the current Linux implementation these mapping tables live
46  * inside the kernel; NetLabel provides a mechanism for user space applications
47  * to manage these mapping tables.
48  *
49  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
50  * send messages between kernel and user space.  The general format of a
51  * NetLabel message is shown below:
52  *
53  *  +-----------------+-------------------+--------- --- -- -
54  *  | struct nlmsghdr | struct genlmsghdr | payload
55  *  +-----------------+-------------------+--------- --- -- -
56  *
57  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
58  * The payload is dependent on the subsystem specified in the
59  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
60  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
61  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
62  * the include/net/netlink.h file for more information on NETLINK attributes.
63  *
64  */
65 
66 /*
67  * NetLabel NETLINK protocol
68  */
69 
70 #define NETLBL_PROTO_VERSION            1
71 
72 /* NetLabel NETLINK types/families */
73 #define NETLBL_NLTYPE_NONE              0
74 #define NETLBL_NLTYPE_MGMT              1
75 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
76 #define NETLBL_NLTYPE_RIPSO             2
77 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
78 #define NETLBL_NLTYPE_CIPSOV4           3
79 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
80 #define NETLBL_NLTYPE_CIPSOV6           4
81 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
82 #define NETLBL_NLTYPE_UNLABELED         5
83 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
84 
85 /*
86  * NetLabel - Kernel API for accessing the network packet label mappings.
87  *
88  * The following functions are provided for use by other kernel modules,
89  * specifically kernel LSM modules, to provide a consistent, transparent API
90  * for dealing with explicit packet labeling protocols such as CIPSO and
91  * RIPSO.  The functions defined here are implemented in the
92  * net/netlabel/netlabel_kapi.c file.
93  *
94  */
95 
96 /* NetLabel audit information */
97 struct netlbl_audit {
98 	u32 secid;
99 	uid_t loginuid;
100 };
101 
102 /* Domain mapping definition struct */
103 struct netlbl_dom_map;
104 
105 /* Domain mapping operations */
106 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info);
107 
108 /* LSM security attributes */
109 struct netlbl_lsm_cache {
110 	atomic_t refcount;
111 	void (*free) (const void *data);
112 	void *data;
113 };
114 /* The catmap bitmap field MUST be a power of two in length and large
115  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
116  * should be used when changing these values as the LSM implementation
117  * probably has functions which rely on the sizes of these types to speed
118  * processing. */
119 #define NETLBL_CATMAP_MAPTYPE           u64
120 #define NETLBL_CATMAP_MAPCNT            4
121 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
122 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
123 					 NETLBL_CATMAP_MAPCNT)
124 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
125 struct netlbl_lsm_secattr_catmap {
126 	u32 startbit;
127 	NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
128 	struct netlbl_lsm_secattr_catmap *next;
129 };
130 #define NETLBL_SECATTR_NONE             0x00000000
131 #define NETLBL_SECATTR_DOMAIN           0x00000001
132 #define NETLBL_SECATTR_CACHE            0x00000002
133 #define NETLBL_SECATTR_MLS_LVL          0x00000004
134 #define NETLBL_SECATTR_MLS_CAT          0x00000008
135 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
136 					 NETLBL_SECATTR_MLS_CAT)
137 struct netlbl_lsm_secattr {
138 	u32 flags;
139 
140 	char *domain;
141 
142 	u32 mls_lvl;
143 	struct netlbl_lsm_secattr_catmap *mls_cat;
144 
145 	struct netlbl_lsm_cache *cache;
146 };
147 
148 /*
149  * LSM security attribute operations (inline)
150  */
151 
152 /**
153  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
154  * @flags: the memory allocation flags
155  *
156  * Description:
157  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
158  * on success, NULL on failure.
159  *
160  */
161 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
162 {
163 	struct netlbl_lsm_cache *cache;
164 
165 	cache = kzalloc(sizeof(*cache), flags);
166 	if (cache)
167 		atomic_set(&cache->refcount, 1);
168 	return cache;
169 }
170 
171 /**
172  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
173  * @cache: the struct to free
174  *
175  * Description:
176  * Frees @secattr including all of the internal buffers.
177  *
178  */
179 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
180 {
181 	if (!atomic_dec_and_test(&cache->refcount))
182 		return;
183 
184 	if (cache->free)
185 		cache->free(cache->data);
186 	kfree(cache);
187 }
188 
189 /**
190  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
191  * @flags: memory allocation flags
192  *
193  * Description:
194  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
195  * on failure.
196  *
197  */
198 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
199 	                                                           gfp_t flags)
200 {
201 	return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
202 }
203 
204 /**
205  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
206  * @catmap: the category bitmap
207  *
208  * Description:
209  * Free a LSM secattr catmap.
210  *
211  */
212 static inline void netlbl_secattr_catmap_free(
213 	                              struct netlbl_lsm_secattr_catmap *catmap)
214 {
215 	struct netlbl_lsm_secattr_catmap *iter;
216 
217 	do {
218 		iter = catmap;
219 		catmap = catmap->next;
220 		kfree(iter);
221 	} while (catmap);
222 }
223 
224 /**
225  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
226  * @secattr: the struct to initialize
227  *
228  * Description:
229  * Initialize an already allocated netlbl_lsm_secattr struct.
230  *
231  */
232 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
233 {
234 	secattr->flags = 0;
235 	secattr->domain = NULL;
236 	secattr->mls_cat = NULL;
237 	secattr->cache = NULL;
238 }
239 
240 /**
241  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
242  * @secattr: the struct to clear
243  *
244  * Description:
245  * Destroys the @secattr struct, including freeing all of the internal buffers.
246  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
247  *
248  */
249 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
250 {
251 	if (secattr->cache)
252 		netlbl_secattr_cache_free(secattr->cache);
253 	kfree(secattr->domain);
254 	if (secattr->mls_cat)
255 		netlbl_secattr_catmap_free(secattr->mls_cat);
256 }
257 
258 /**
259  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
260  * @flags: the memory allocation flags
261  *
262  * Description:
263  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
264  * pointer on success, or NULL on failure.
265  *
266  */
267 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
268 {
269 	return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
270 }
271 
272 /**
273  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
274  * @secattr: the struct to free
275  *
276  * Description:
277  * Frees @secattr including all of the internal buffers.
278  *
279  */
280 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
281 {
282 	netlbl_secattr_destroy(secattr);
283 	kfree(secattr);
284 }
285 
286 #ifdef CONFIG_NETLABEL
287 /*
288  * LSM security attribute operations
289  */
290 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
291 			       u32 offset);
292 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
293 				   u32 offset);
294 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
295 				 u32 bit,
296 				 gfp_t flags);
297 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
298 				 u32 start,
299 				 u32 end,
300 				 gfp_t flags);
301 
302 /*
303  * LSM protocol operations
304  */
305 int netlbl_enabled(void);
306 int netlbl_sock_setattr(struct sock *sk,
307 			const struct netlbl_lsm_secattr *secattr);
308 int netlbl_sock_getattr(struct sock *sk,
309 			struct netlbl_lsm_secattr *secattr);
310 int netlbl_skbuff_getattr(const struct sk_buff *skb,
311 			  struct netlbl_lsm_secattr *secattr);
312 void netlbl_skbuff_err(struct sk_buff *skb, int error);
313 
314 /*
315  * LSM label mapping cache operations
316  */
317 void netlbl_cache_invalidate(void);
318 int netlbl_cache_add(const struct sk_buff *skb,
319 		     const struct netlbl_lsm_secattr *secattr);
320 #else
321 static inline int netlbl_secattr_catmap_walk(
322 	                              struct netlbl_lsm_secattr_catmap *catmap,
323 				      u32 offset)
324 {
325 	return -ENOENT;
326 }
327 static inline int netlbl_secattr_catmap_walk_rng(
328 				      struct netlbl_lsm_secattr_catmap *catmap,
329 				      u32 offset)
330 {
331 	return -ENOENT;
332 }
333 static inline int netlbl_secattr_catmap_setbit(
334 	                              struct netlbl_lsm_secattr_catmap *catmap,
335 				      u32 bit,
336 				      gfp_t flags)
337 {
338 	return 0;
339 }
340 static inline int netlbl_secattr_catmap_setrng(
341 	                              struct netlbl_lsm_secattr_catmap *catmap,
342 				      u32 start,
343 				      u32 end,
344 				      gfp_t flags)
345 {
346 	return 0;
347 }
348 static inline int netlbl_enabled(void)
349 {
350 	return 0;
351 }
352 static inline int netlbl_sock_setattr(struct sock *sk,
353 				     const struct netlbl_lsm_secattr *secattr)
354 {
355 	return -ENOSYS;
356 }
357 static inline int netlbl_sock_getattr(struct sock *sk,
358 				      struct netlbl_lsm_secattr *secattr)
359 {
360 	return -ENOSYS;
361 }
362 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
363 					struct netlbl_lsm_secattr *secattr)
364 {
365 	return -ENOSYS;
366 }
367 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
368 {
369 	return;
370 }
371 static inline void netlbl_cache_invalidate(void)
372 {
373 	return;
374 }
375 static inline int netlbl_cache_add(const struct sk_buff *skb,
376 				   const struct netlbl_lsm_secattr *secattr)
377 {
378 	return 0;
379 }
380 #endif /* CONFIG_NETLABEL */
381 
382 #endif /* _NETLABEL_H */
383