xref: /openbmc/linux/include/net/cipso_ipv4.h (revision 1edd0337)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * CIPSO - Commercial IP Security Option
4  *
5  * This is an implementation of the CIPSO 2.2 protocol as specified in
6  * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
7  * FIPS-188, copies of both documents can be found in the Documentation
8  * directory.  While CIPSO never became a full IETF RFC standard many vendors
9  * have chosen to adopt the protocol and over the years it has become a
10  * de-facto standard for labeled networking.
11  *
12  * Author: Paul Moore <paul@paul-moore.com>
13  */
14 
15 /*
16  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
17  */
18 
19 #ifndef _CIPSO_IPV4_H
20 #define _CIPSO_IPV4_H
21 
22 #include <linux/types.h>
23 #include <linux/rcupdate.h>
24 #include <linux/list.h>
25 #include <linux/net.h>
26 #include <linux/skbuff.h>
27 #include <net/netlabel.h>
28 #include <net/request_sock.h>
29 #include <linux/atomic.h>
30 #include <linux/refcount.h>
31 #include <asm/unaligned.h>
32 
33 /* known doi values */
34 #define CIPSO_V4_DOI_UNKNOWN          0x00000000
35 
36 /* standard tag types */
37 #define CIPSO_V4_TAG_INVALID          0
38 #define CIPSO_V4_TAG_RBITMAP          1
39 #define CIPSO_V4_TAG_ENUM             2
40 #define CIPSO_V4_TAG_RANGE            5
41 #define CIPSO_V4_TAG_PBITMAP          6
42 #define CIPSO_V4_TAG_FREEFORM         7
43 
44 /* non-standard tag types (tags > 127) */
45 #define CIPSO_V4_TAG_LOCAL            128
46 
47 /* doi mapping types */
48 #define CIPSO_V4_MAP_UNKNOWN          0
49 #define CIPSO_V4_MAP_TRANS            1
50 #define CIPSO_V4_MAP_PASS             2
51 #define CIPSO_V4_MAP_LOCAL            3
52 
53 /* limits */
54 #define CIPSO_V4_MAX_REM_LVLS         255
55 #define CIPSO_V4_INV_LVL              0x80000000
56 #define CIPSO_V4_MAX_LOC_LVLS         (CIPSO_V4_INV_LVL - 1)
57 #define CIPSO_V4_MAX_REM_CATS         65534
58 #define CIPSO_V4_INV_CAT              0x80000000
59 #define CIPSO_V4_MAX_LOC_CATS         (CIPSO_V4_INV_CAT - 1)
60 
61 /*
62  * CIPSO DOI definitions
63  */
64 
65 /* DOI definition struct */
66 #define CIPSO_V4_TAG_MAXCNT           5
67 struct cipso_v4_doi {
68 	u32 doi;
69 	u32 type;
70 	union {
71 		struct cipso_v4_std_map_tbl *std;
72 	} map;
73 	u8 tags[CIPSO_V4_TAG_MAXCNT];
74 
75 	refcount_t refcount;
76 	struct list_head list;
77 	struct rcu_head rcu;
78 };
79 
80 /* Standard CIPSO mapping table */
81 /* NOTE: the highest order bit (i.e. 0x80000000) is an 'invalid' flag, if the
82  *       bit is set then consider that value as unspecified, meaning the
83  *       mapping for that particular level/category is invalid */
84 struct cipso_v4_std_map_tbl {
85 	struct {
86 		u32 *cipso;
87 		u32 *local;
88 		u32 cipso_size;
89 		u32 local_size;
90 	} lvl;
91 	struct {
92 		u32 *cipso;
93 		u32 *local;
94 		u32 cipso_size;
95 		u32 local_size;
96 	} cat;
97 };
98 
99 /*
100  * Sysctl Variables
101  */
102 
103 #ifdef CONFIG_NETLABEL
104 extern int cipso_v4_cache_enabled;
105 extern int cipso_v4_cache_bucketsize;
106 extern int cipso_v4_rbm_optfmt;
107 extern int cipso_v4_rbm_strictvalid;
108 #endif
109 
110 /*
111  * DOI List Functions
112  */
113 
114 #ifdef CONFIG_NETLABEL
115 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
116 		     struct netlbl_audit *audit_info);
117 void cipso_v4_doi_free(struct cipso_v4_doi *doi_def);
118 int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info);
119 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi);
120 void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def);
121 int cipso_v4_doi_walk(u32 *skip_cnt,
122 		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
123 	             void *cb_arg);
124 #else
125 static inline int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
126 				   struct netlbl_audit *audit_info)
127 {
128 	return -ENOSYS;
129 }
130 
131 static inline void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
132 {
133 	return;
134 }
135 
136 static inline int cipso_v4_doi_remove(u32 doi,
137 				      struct netlbl_audit *audit_info)
138 {
139 	return 0;
140 }
141 
142 static inline struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
143 {
144 	return NULL;
145 }
146 
147 static inline int cipso_v4_doi_walk(u32 *skip_cnt,
148 		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
149 		     void *cb_arg)
150 {
151 	return 0;
152 }
153 #endif /* CONFIG_NETLABEL */
154 
155 /*
156  * Label Mapping Cache Functions
157  */
158 
159 #ifdef CONFIG_NETLABEL
160 void cipso_v4_cache_invalidate(void);
161 int cipso_v4_cache_add(const unsigned char *cipso_ptr,
162 		       const struct netlbl_lsm_secattr *secattr);
163 #else
164 static inline void cipso_v4_cache_invalidate(void)
165 {
166 	return;
167 }
168 
169 static inline int cipso_v4_cache_add(const unsigned char *cipso_ptr,
170 				     const struct netlbl_lsm_secattr *secattr)
171 {
172 	return 0;
173 }
174 #endif /* CONFIG_NETLABEL */
175 
176 /*
177  * Protocol Handling Functions
178  */
179 
180 #ifdef CONFIG_NETLABEL
181 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway);
182 int cipso_v4_getattr(const unsigned char *cipso,
183 		     struct netlbl_lsm_secattr *secattr);
184 int cipso_v4_sock_setattr(struct sock *sk,
185 			  const struct cipso_v4_doi *doi_def,
186 			  const struct netlbl_lsm_secattr *secattr);
187 void cipso_v4_sock_delattr(struct sock *sk);
188 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr);
189 int cipso_v4_req_setattr(struct request_sock *req,
190 			 const struct cipso_v4_doi *doi_def,
191 			 const struct netlbl_lsm_secattr *secattr);
192 void cipso_v4_req_delattr(struct request_sock *req);
193 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
194 			    const struct cipso_v4_doi *doi_def,
195 			    const struct netlbl_lsm_secattr *secattr);
196 int cipso_v4_skbuff_delattr(struct sk_buff *skb);
197 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
198 			    struct netlbl_lsm_secattr *secattr);
199 unsigned char *cipso_v4_optptr(const struct sk_buff *skb);
200 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option);
201 #else
202 static inline void cipso_v4_error(struct sk_buff *skb,
203 				  int error,
204 				  u32 gateway)
205 {
206 	return;
207 }
208 
209 static inline int cipso_v4_getattr(const unsigned char *cipso,
210 				   struct netlbl_lsm_secattr *secattr)
211 {
212 	return -ENOSYS;
213 }
214 
215 static inline int cipso_v4_sock_setattr(struct sock *sk,
216 				      const struct cipso_v4_doi *doi_def,
217 				      const struct netlbl_lsm_secattr *secattr)
218 {
219 	return -ENOSYS;
220 }
221 
222 static inline void cipso_v4_sock_delattr(struct sock *sk)
223 {
224 }
225 
226 static inline int cipso_v4_sock_getattr(struct sock *sk,
227 					struct netlbl_lsm_secattr *secattr)
228 {
229 	return -ENOSYS;
230 }
231 
232 static inline int cipso_v4_req_setattr(struct request_sock *req,
233 				       const struct cipso_v4_doi *doi_def,
234 				       const struct netlbl_lsm_secattr *secattr)
235 {
236 	return -ENOSYS;
237 }
238 
239 static inline void cipso_v4_req_delattr(struct request_sock *req)
240 {
241 	return;
242 }
243 
244 static inline int cipso_v4_skbuff_setattr(struct sk_buff *skb,
245 				      const struct cipso_v4_doi *doi_def,
246 				      const struct netlbl_lsm_secattr *secattr)
247 {
248 	return -ENOSYS;
249 }
250 
251 static inline int cipso_v4_skbuff_delattr(struct sk_buff *skb)
252 {
253 	return -ENOSYS;
254 }
255 
256 static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
257 					  struct netlbl_lsm_secattr *secattr)
258 {
259 	return -ENOSYS;
260 }
261 
262 static inline unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
263 {
264 	return NULL;
265 }
266 
267 static inline int cipso_v4_validate(const struct sk_buff *skb,
268 				    unsigned char **option)
269 {
270 	unsigned char *opt = *option;
271 	unsigned char err_offset = 0;
272 	u8 opt_len = opt[1];
273 	u8 opt_iter;
274 	u8 tag_len;
275 
276 	if (opt_len < 8) {
277 		err_offset = 1;
278 		goto out;
279 	}
280 
281 	if (get_unaligned_be32(&opt[2]) == 0) {
282 		err_offset = 2;
283 		goto out;
284 	}
285 
286 	for (opt_iter = 6; opt_iter < opt_len;) {
287 		if (opt_iter + 1 == opt_len) {
288 			err_offset = opt_iter;
289 			goto out;
290 		}
291 		tag_len = opt[opt_iter + 1];
292 		if ((tag_len == 0) || (tag_len > (opt_len - opt_iter))) {
293 			err_offset = opt_iter + 1;
294 			goto out;
295 		}
296 		opt_iter += tag_len;
297 	}
298 
299 out:
300 	*option = opt + err_offset;
301 	return err_offset;
302 
303 }
304 #endif /* CONFIG_NETLABEL */
305 
306 #endif /* _CIPSO_IPV4_H */
307