1/*
2 * CIPSO - Commercial IP Security Option
3 *
4 * This is an implementation of the CIPSO 2.2 protocol as specified in
5 * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
6 * FIPS-188, copies of both documents can be found in the Documentation
7 * directory.  While CIPSO never became a full IETF RFC standard many vendors
8 * have chosen to adopt the protocol and over the years it has become a
9 * de-facto standard for labeled networking.
10 *
11 * Author: Paul Moore <paul@paul-moore.com>
12 *
13 */
14
15/*
16 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
17 *
18 * This program is free software;  you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
26 * the GNU General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program;  if not, see <http://www.gnu.org/licenses/>.
30 *
31 */
32
33#ifndef _CIPSO_IPV4_H
34#define _CIPSO_IPV4_H
35
36#include <linux/types.h>
37#include <linux/rcupdate.h>
38#include <linux/list.h>
39#include <linux/net.h>
40#include <linux/skbuff.h>
41#include <net/netlabel.h>
42#include <net/request_sock.h>
43#include <linux/atomic.h>
44#include <asm/unaligned.h>
45
46/* known doi values */
47#define CIPSO_V4_DOI_UNKNOWN          0x00000000
48
49/* standard tag types */
50#define CIPSO_V4_TAG_INVALID          0
51#define CIPSO_V4_TAG_RBITMAP          1
52#define CIPSO_V4_TAG_ENUM             2
53#define CIPSO_V4_TAG_RANGE            5
54#define CIPSO_V4_TAG_PBITMAP          6
55#define CIPSO_V4_TAG_FREEFORM         7
56
57/* non-standard tag types (tags > 127) */
58#define CIPSO_V4_TAG_LOCAL            128
59
60/* doi mapping types */
61#define CIPSO_V4_MAP_UNKNOWN          0
62#define CIPSO_V4_MAP_TRANS            1
63#define CIPSO_V4_MAP_PASS             2
64#define CIPSO_V4_MAP_LOCAL            3
65
66/* limits */
67#define CIPSO_V4_MAX_REM_LVLS         255
68#define CIPSO_V4_INV_LVL              0x80000000
69#define CIPSO_V4_MAX_LOC_LVLS         (CIPSO_V4_INV_LVL - 1)
70#define CIPSO_V4_MAX_REM_CATS         65534
71#define CIPSO_V4_INV_CAT              0x80000000
72#define CIPSO_V4_MAX_LOC_CATS         (CIPSO_V4_INV_CAT - 1)
73
74/*
75 * CIPSO DOI definitions
76 */
77
78/* DOI definition struct */
79#define CIPSO_V4_TAG_MAXCNT           5
80struct cipso_v4_doi {
81	u32 doi;
82	u32 type;
83	union {
84		struct cipso_v4_std_map_tbl *std;
85	} map;
86	u8 tags[CIPSO_V4_TAG_MAXCNT];
87
88	atomic_t refcount;
89	struct list_head list;
90	struct rcu_head rcu;
91};
92
93/* Standard CIPSO mapping table */
94/* NOTE: the highest order bit (i.e. 0x80000000) is an 'invalid' flag, if the
95 *       bit is set then consider that value as unspecified, meaning the
96 *       mapping for that particular level/category is invalid */
97struct cipso_v4_std_map_tbl {
98	struct {
99		u32 *cipso;
100		u32 *local;
101		u32 cipso_size;
102		u32 local_size;
103	} lvl;
104	struct {
105		u32 *cipso;
106		u32 *local;
107		u32 cipso_size;
108		u32 local_size;
109	} cat;
110};
111
112/*
113 * Sysctl Variables
114 */
115
116#ifdef CONFIG_NETLABEL
117extern int cipso_v4_cache_enabled;
118extern int cipso_v4_cache_bucketsize;
119extern int cipso_v4_rbm_optfmt;
120extern int cipso_v4_rbm_strictvalid;
121#endif
122
123/*
124 * DOI List Functions
125 */
126
127#ifdef CONFIG_NETLABEL
128int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
129		     struct netlbl_audit *audit_info);
130void cipso_v4_doi_free(struct cipso_v4_doi *doi_def);
131int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info);
132struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi);
133void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def);
134int cipso_v4_doi_walk(u32 *skip_cnt,
135		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
136	             void *cb_arg);
137#else
138static inline int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
139				   struct netlbl_audit *audit_info)
140{
141	return -ENOSYS;
142}
143
144static inline void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
145{
146	return;
147}
148
149static inline int cipso_v4_doi_remove(u32 doi,
150				      struct netlbl_audit *audit_info)
151{
152	return 0;
153}
154
155static inline struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
156{
157	return NULL;
158}
159
160static inline int cipso_v4_doi_walk(u32 *skip_cnt,
161		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
162		     void *cb_arg)
163{
164	return 0;
165}
166
167static inline int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def,
168					  const char *domain)
169{
170	return -ENOSYS;
171}
172
173static inline int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def,
174					     const char *domain)
175{
176	return 0;
177}
178#endif /* CONFIG_NETLABEL */
179
180/*
181 * Label Mapping Cache Functions
182 */
183
184#ifdef CONFIG_NETLABEL
185void cipso_v4_cache_invalidate(void);
186int cipso_v4_cache_add(const unsigned char *cipso_ptr,
187		       const struct netlbl_lsm_secattr *secattr);
188#else
189static inline void cipso_v4_cache_invalidate(void)
190{
191	return;
192}
193
194static inline int cipso_v4_cache_add(const unsigned char *cipso_ptr,
195				     const struct netlbl_lsm_secattr *secattr)
196{
197	return 0;
198}
199#endif /* CONFIG_NETLABEL */
200
201/*
202 * Protocol Handling Functions
203 */
204
205#ifdef CONFIG_NETLABEL
206void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway);
207int cipso_v4_getattr(const unsigned char *cipso,
208		     struct netlbl_lsm_secattr *secattr);
209int cipso_v4_sock_setattr(struct sock *sk,
210			  const struct cipso_v4_doi *doi_def,
211			  const struct netlbl_lsm_secattr *secattr);
212void cipso_v4_sock_delattr(struct sock *sk);
213int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr);
214int cipso_v4_req_setattr(struct request_sock *req,
215			 const struct cipso_v4_doi *doi_def,
216			 const struct netlbl_lsm_secattr *secattr);
217void cipso_v4_req_delattr(struct request_sock *req);
218int cipso_v4_skbuff_setattr(struct sk_buff *skb,
219			    const struct cipso_v4_doi *doi_def,
220			    const struct netlbl_lsm_secattr *secattr);
221int cipso_v4_skbuff_delattr(struct sk_buff *skb);
222int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
223			    struct netlbl_lsm_secattr *secattr);
224unsigned char *cipso_v4_optptr(const struct sk_buff *skb);
225int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option);
226#else
227static inline void cipso_v4_error(struct sk_buff *skb,
228				  int error,
229				  u32 gateway)
230{
231	return;
232}
233
234static inline int cipso_v4_getattr(const unsigned char *cipso,
235				   struct netlbl_lsm_secattr *secattr)
236{
237	return -ENOSYS;
238}
239
240static inline int cipso_v4_sock_setattr(struct sock *sk,
241				      const struct cipso_v4_doi *doi_def,
242				      const struct netlbl_lsm_secattr *secattr)
243{
244	return -ENOSYS;
245}
246
247static inline void cipso_v4_sock_delattr(struct sock *sk)
248{
249}
250
251static inline int cipso_v4_sock_getattr(struct sock *sk,
252					struct netlbl_lsm_secattr *secattr)
253{
254	return -ENOSYS;
255}
256
257static inline int cipso_v4_req_setattr(struct request_sock *req,
258				       const struct cipso_v4_doi *doi_def,
259				       const struct netlbl_lsm_secattr *secattr)
260{
261	return -ENOSYS;
262}
263
264static inline void cipso_v4_req_delattr(struct request_sock *req)
265{
266	return;
267}
268
269static inline int cipso_v4_skbuff_setattr(struct sk_buff *skb,
270				      const struct cipso_v4_doi *doi_def,
271				      const struct netlbl_lsm_secattr *secattr)
272{
273	return -ENOSYS;
274}
275
276static inline int cipso_v4_skbuff_delattr(struct sk_buff *skb)
277{
278	return -ENOSYS;
279}
280
281static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
282					  struct netlbl_lsm_secattr *secattr)
283{
284	return -ENOSYS;
285}
286
287static inline unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
288{
289	return NULL;
290}
291
292static inline int cipso_v4_validate(const struct sk_buff *skb,
293				    unsigned char **option)
294{
295	unsigned char *opt = *option;
296	unsigned char err_offset = 0;
297	u8 opt_len = opt[1];
298	u8 opt_iter;
299	u8 tag_len;
300
301	if (opt_len < 8) {
302		err_offset = 1;
303		goto out;
304	}
305
306	if (get_unaligned_be32(&opt[2]) == 0) {
307		err_offset = 2;
308		goto out;
309	}
310
311	for (opt_iter = 6; opt_iter < opt_len;) {
312		tag_len = opt[opt_iter + 1];
313		if ((tag_len == 0) || (tag_len > (opt_len - opt_iter))) {
314			err_offset = opt_iter + 1;
315			goto out;
316		}
317		opt_iter += tag_len;
318	}
319
320out:
321	*option = opt + err_offset;
322	return err_offset;
323
324}
325#endif /* CONFIG_NETLABEL */
326
327#endif /* _CIPSO_IPV4_H */
328