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 <linux/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
cipso_v4_doi_add(struct cipso_v4_doi * doi_def,struct netlbl_audit * audit_info)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 
cipso_v4_doi_free(struct cipso_v4_doi * doi_def)131 static inline void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
132 {
133 	return;
134 }
135 
cipso_v4_doi_remove(u32 doi,struct netlbl_audit * audit_info)136 static inline int cipso_v4_doi_remove(u32 doi,
137 				      struct netlbl_audit *audit_info)
138 {
139 	return 0;
140 }
141 
cipso_v4_doi_getdef(u32 doi)142 static inline struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
143 {
144 	return NULL;
145 }
146 
cipso_v4_doi_walk(u32 * skip_cnt,int (* callback)(struct cipso_v4_doi * doi_def,void * arg),void * cb_arg)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
cipso_v4_cache_invalidate(void)164 static inline void cipso_v4_cache_invalidate(void)
165 {
166 	return;
167 }
168 
cipso_v4_cache_add(const unsigned char * cipso_ptr,const struct netlbl_lsm_secattr * secattr)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 			  bool sk_locked);
188 void cipso_v4_sock_delattr(struct sock *sk);
189 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr);
190 int cipso_v4_req_setattr(struct request_sock *req,
191 			 const struct cipso_v4_doi *doi_def,
192 			 const struct netlbl_lsm_secattr *secattr);
193 void cipso_v4_req_delattr(struct request_sock *req);
194 int cipso_v4_skbuff_setattr(struct sk_buff *skb,
195 			    const struct cipso_v4_doi *doi_def,
196 			    const struct netlbl_lsm_secattr *secattr);
197 int cipso_v4_skbuff_delattr(struct sk_buff *skb);
198 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
199 			    struct netlbl_lsm_secattr *secattr);
200 unsigned char *cipso_v4_optptr(const struct sk_buff *skb);
201 int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option);
202 #else
cipso_v4_error(struct sk_buff * skb,int error,u32 gateway)203 static inline void cipso_v4_error(struct sk_buff *skb,
204 				  int error,
205 				  u32 gateway)
206 {
207 	return;
208 }
209 
cipso_v4_getattr(const unsigned char * cipso,struct netlbl_lsm_secattr * secattr)210 static inline int cipso_v4_getattr(const unsigned char *cipso,
211 				   struct netlbl_lsm_secattr *secattr)
212 {
213 	return -ENOSYS;
214 }
215 
cipso_v4_sock_setattr(struct sock * sk,const struct cipso_v4_doi * doi_def,const struct netlbl_lsm_secattr * secattr,bool sk_locked)216 static inline int cipso_v4_sock_setattr(struct sock *sk,
217 				      const struct cipso_v4_doi *doi_def,
218 				      const struct netlbl_lsm_secattr *secattr,
219 				      bool sk_locked)
220 {
221 	return -ENOSYS;
222 }
223 
cipso_v4_sock_delattr(struct sock * sk)224 static inline void cipso_v4_sock_delattr(struct sock *sk)
225 {
226 }
227 
cipso_v4_sock_getattr(struct sock * sk,struct netlbl_lsm_secattr * secattr)228 static inline int cipso_v4_sock_getattr(struct sock *sk,
229 					struct netlbl_lsm_secattr *secattr)
230 {
231 	return -ENOSYS;
232 }
233 
cipso_v4_req_setattr(struct request_sock * req,const struct cipso_v4_doi * doi_def,const struct netlbl_lsm_secattr * secattr)234 static inline int cipso_v4_req_setattr(struct request_sock *req,
235 				       const struct cipso_v4_doi *doi_def,
236 				       const struct netlbl_lsm_secattr *secattr)
237 {
238 	return -ENOSYS;
239 }
240 
cipso_v4_req_delattr(struct request_sock * req)241 static inline void cipso_v4_req_delattr(struct request_sock *req)
242 {
243 	return;
244 }
245 
cipso_v4_skbuff_setattr(struct sk_buff * skb,const struct cipso_v4_doi * doi_def,const struct netlbl_lsm_secattr * secattr)246 static inline int cipso_v4_skbuff_setattr(struct sk_buff *skb,
247 				      const struct cipso_v4_doi *doi_def,
248 				      const struct netlbl_lsm_secattr *secattr)
249 {
250 	return -ENOSYS;
251 }
252 
cipso_v4_skbuff_delattr(struct sk_buff * skb)253 static inline int cipso_v4_skbuff_delattr(struct sk_buff *skb)
254 {
255 	return -ENOSYS;
256 }
257 
cipso_v4_skbuff_getattr(const struct sk_buff * skb,struct netlbl_lsm_secattr * secattr)258 static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
259 					  struct netlbl_lsm_secattr *secattr)
260 {
261 	return -ENOSYS;
262 }
263 
cipso_v4_optptr(const struct sk_buff * skb)264 static inline unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
265 {
266 	return NULL;
267 }
268 
cipso_v4_validate(const struct sk_buff * skb,unsigned char ** option)269 static inline int cipso_v4_validate(const struct sk_buff *skb,
270 				    unsigned char **option)
271 {
272 	unsigned char *opt = *option;
273 	unsigned char err_offset = 0;
274 	u8 opt_len = opt[1];
275 	u8 opt_iter;
276 	u8 tag_len;
277 
278 	if (opt_len < 8) {
279 		err_offset = 1;
280 		goto out;
281 	}
282 
283 	if (get_unaligned_be32(&opt[2]) == 0) {
284 		err_offset = 2;
285 		goto out;
286 	}
287 
288 	for (opt_iter = 6; opt_iter < opt_len;) {
289 		if (opt_iter + 1 == opt_len) {
290 			err_offset = opt_iter;
291 			goto out;
292 		}
293 		tag_len = opt[opt_iter + 1];
294 		if ((tag_len == 0) || (tag_len > (opt_len - opt_iter))) {
295 			err_offset = opt_iter + 1;
296 			goto out;
297 		}
298 		opt_iter += tag_len;
299 	}
300 
301 out:
302 	*option = opt + err_offset;
303 	return err_offset;
304 
305 }
306 #endif /* CONFIG_NETLABEL */
307 
308 #endif /* _CIPSO_IPV4_H */
309