xref: /freebsd/sys/security/mac/mac_internal.h (revision f856af0466c076beef4ea9b15d088e1119a945b8)
1 /*-
2  * Copyright (c) 1999-2002 Robert N. M. Watson
3  * Copyright (c) 2001 Ilmar S. Habibulin
4  * Copyright (c) 2001-2004 Networks Associates Technology, Inc.
5  * Copyright (c) 2006 nCircle Network Security, Inc.
6  * All rights reserved.
7  *
8  * This software was developed by Robert Watson and Ilmar Habibulin for the
9  * TrustedBSD Project.
10  *
11  * This software was developed for the FreeBSD Project in part by Network
12  * Associates Laboratories, the Security Research Division of Network
13  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
14  * as part of the DARPA CHATS research program.
15  *
16  * This software was developed by Robert N. M. Watson for the TrustedBSD
17  * Project under contract to nCircle Network Security, Inc.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  * $FreeBSD$
41  */
42 
43 #ifndef _SYS_SECURITY_MAC_MAC_INTERNAL_H_
44 #define	_SYS_SECURITY_MAC_MAC_INTERNAL_H_
45 
46 /*
47  * MAC Framework sysctl namespace.
48  */
49 #ifdef SYSCTL_DECL
50 SYSCTL_DECL(_security_mac);
51 #endif /* SYSCTL_DECL */
52 
53 /*
54  * MAC Framework global types and typedefs.
55  */
56 LIST_HEAD(mac_policy_list_head, mac_policy_conf);
57 #ifdef MALLOC_DECLARE
58 MALLOC_DECLARE(M_MACTEMP);
59 #endif
60 
61 /*
62  * MAC Framework global variables.
63  */
64 extern struct mac_policy_list_head	mac_policy_list;
65 extern struct mac_policy_list_head	mac_static_policy_list;
66 #ifndef MAC_ALWAYS_LABEL_MBUF
67 extern int				mac_labelmbufs;
68 #endif
69 
70 /*
71  * MAC Framework infrastructure functions.
72  */
73 int	mac_error_select(int error1, int error2);
74 
75 void	mac_policy_grab_exclusive(void);
76 void	mac_policy_assert_exclusive(void);
77 void	mac_policy_release_exclusive(void);
78 void	mac_policy_list_busy(void);
79 int	mac_policy_list_conditional_busy(void);
80 void	mac_policy_list_unbusy(void);
81 
82 struct label	*mac_labelzone_alloc(int flags);
83 void		 mac_labelzone_free(struct label *label);
84 void		 mac_labelzone_init(void);
85 
86 void	mac_init_label(struct label *label);
87 void	mac_destroy_label(struct label *label);
88 int	mac_check_structmac_consistent(struct mac *mac);
89 int	mac_allocate_slot(void);
90 
91 /*
92  * MAC Framework per-object type functions.  It's not yet clear how the
93  * namespaces, etc, should work for these, so for now, sort by object type.
94  */
95 struct label	*mac_pipe_label_alloc(void);
96 void		 mac_pipe_label_free(struct label *label);
97 struct label	*mac_socket_label_alloc(int flag);
98 void		 mac_socket_label_free(struct label *label);
99 
100 int	mac_check_cred_relabel(struct ucred *cred, struct label *newlabel);
101 int	mac_externalize_cred_label(struct label *label, char *elements,
102 	    char *outbuf, size_t outbuflen);
103 int	mac_internalize_cred_label(struct label *label, char *string);
104 void	mac_relabel_cred(struct ucred *cred, struct label *newlabel);
105 
106 struct label	*mac_mbuf_to_label(struct mbuf *m);
107 
108 void	mac_copy_pipe_label(struct label *src, struct label *dest);
109 int	mac_externalize_pipe_label(struct label *label, char *elements,
110 	    char *outbuf, size_t outbuflen);
111 int	mac_internalize_pipe_label(struct label *label, char *string);
112 
113 int	mac_socket_label_set(struct ucred *cred, struct socket *so,
114 	    struct label *label);
115 void	mac_copy_socket_label(struct label *src, struct label *dest);
116 int	mac_externalize_socket_label(struct label *label, char *elements,
117 	    char *outbuf, size_t outbuflen);
118 int	mac_internalize_socket_label(struct label *label, char *string);
119 
120 int	mac_externalize_vnode_label(struct label *label, char *elements,
121 	    char *outbuf, size_t outbuflen);
122 int	mac_internalize_vnode_label(struct label *label, char *string);
123 void	mac_check_vnode_mmap_downgrade(struct ucred *cred, struct vnode *vp,
124 	    int *prot);
125 int	vn_setlabel(struct vnode *vp, struct label *intlabel,
126 	    struct ucred *cred);
127 
128 /*
129  * MAC_CHECK performs the designated check by walking the policy module list
130  * and checking with each as to how it feels about the request.  Note that it
131  * returns its value via 'error' in the scope of the caller.
132  */
133 #define	MAC_CHECK(check, args...) do {					\
134 	struct mac_policy_conf *mpc;					\
135 	int entrycount;							\
136 									\
137 	error = 0;							\
138 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
139 		if (mpc->mpc_ops->mpo_ ## check != NULL)		\
140 			error = mac_error_select(			\
141 			    mpc->mpc_ops->mpo_ ## check (args),		\
142 			    error);					\
143 	}								\
144 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
145 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
146 			if (mpc->mpc_ops->mpo_ ## check != NULL)	\
147 				error = mac_error_select(		\
148 				    mpc->mpc_ops->mpo_ ## check (args),	\
149 				    error);				\
150 		}							\
151 		mac_policy_list_unbusy();				\
152 	}								\
153 } while (0)
154 
155 /*
156  * MAC_GRANT performs the designated check by walking the policy module list
157  * and checking with each as to how it feels about the request.  Unlike
158  * MAC_CHECK, it grants if any policies return '0', and otherwise returns
159  * EPERM.  Note that it returns its value via 'error' in the scope of the
160  * caller.
161  */
162 #define	MAC_GRANT(check, args...) do {					\
163 	struct mac_policy_conf *mpc;					\
164 	int entrycount;							\
165 									\
166 	error = EPERM;							\
167 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
168 		if (mpc->mpc_ops->mpo_ ## check != NULL) {		\
169 			if (mpc->mpc_ops->mpo_ ## check(args) == 0)	\
170 				error = 0;				\
171 		}							\
172 	}								\
173 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
174 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
175 			if (mpc->mpc_ops->mpo_ ## check != NULL) {	\
176 				if (mpc->mpc_ops->mpo_ ## check (args)	\
177 				    == 0)				\
178 					error = 0;			\
179 			}						\
180 		}							\
181 		mac_policy_list_unbusy();				\
182 	}								\
183 } while (0)
184 
185 /*
186  * MAC_BOOLEAN performs the designated boolean composition by walking the
187  * module list, invoking each instance of the operation, and combining the
188  * results using the passed C operator.  Note that it returns its value via
189  * 'result' in the scope of the caller, which should be initialized by the
190  * caller in a meaningful way to get a meaningful result.
191  */
192 #define	MAC_BOOLEAN(operation, composition, args...) do {		\
193 	struct mac_policy_conf *mpc;					\
194 	int entrycount;							\
195 									\
196 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
197 		if (mpc->mpc_ops->mpo_ ## operation != NULL)		\
198 			result = result composition			\
199 			    mpc->mpc_ops->mpo_ ## operation (args);	\
200 	}								\
201 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
202 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
203 			if (mpc->mpc_ops->mpo_ ## operation != NULL)	\
204 				result = result composition		\
205 				    mpc->mpc_ops->mpo_ ## operation	\
206 				    (args);				\
207 		}							\
208 		mac_policy_list_unbusy();				\
209 	}								\
210 } while (0)
211 
212 /*
213  * MAC_EXTERNALIZE queries each policy to see if it can generate an
214  * externalized version of a label element by name.  Policies declare whether
215  * they have matched a particular element name, parsed from the string by
216  * MAC_EXTERNALIZE, and an error is returned if any element is matched by no
217  * policy.
218  */
219 #define	MAC_EXTERNALIZE(type, label, elementlist, outbuf, 		\
220     outbuflen) do {							\
221 	int claimed, first, ignorenotfound, savedlen;			\
222 	char *element_name, *element_temp;				\
223 	struct sbuf sb;							\
224 									\
225 	error = 0;							\
226 	first = 1;							\
227 	sbuf_new(&sb, outbuf, outbuflen, SBUF_FIXEDLEN);		\
228 	element_temp = elementlist;					\
229 	while ((element_name = strsep(&element_temp, ",")) != NULL) {	\
230 		if (element_name[0] == '?') {				\
231 			element_name++;					\
232 			ignorenotfound = 1;				\
233 		 } else							\
234 			ignorenotfound = 0;				\
235 		savedlen = sbuf_len(&sb);				\
236 		if (first)						\
237 			error = sbuf_printf(&sb, "%s/", element_name);	\
238 		else							\
239 			error = sbuf_printf(&sb, ",%s/", element_name);	\
240 		if (error == -1) {					\
241 			error = EINVAL;	/* XXX: E2BIG? */		\
242 			break;						\
243 		}							\
244 		claimed = 0;						\
245 		MAC_CHECK(externalize_ ## type ## _label, label,	\
246 		    element_name, &sb, &claimed);			\
247 		if (error)						\
248 			break;						\
249 		if (claimed == 0 && ignorenotfound) {			\
250 			/* Revert last label name. */			\
251 			sbuf_setpos(&sb, savedlen);			\
252 		} else if (claimed != 1) {				\
253 			error = EINVAL;	/* XXX: ENOLABEL? */		\
254 			break;						\
255 		} else {						\
256 			first = 0;					\
257 		}							\
258 	}								\
259 	sbuf_finish(&sb);						\
260 } while (0)
261 
262 /*
263  * MAC_INTERNALIZE presents parsed element names and data to each policy to
264  * see if any is willing to claim it and internalize the label data.  If no
265  * policies match, an error is returned.
266  */
267 #define	MAC_INTERNALIZE(type, label, instring) do {			\
268 	char *element, *element_name, *element_data;			\
269 	int claimed;							\
270 									\
271 	error = 0;							\
272 	element = instring;						\
273 	while ((element_name = strsep(&element, ",")) != NULL) {	\
274 		element_data = element_name;				\
275 		element_name = strsep(&element_data, "/");		\
276 		if (element_data == NULL) {				\
277 			error = EINVAL;					\
278 			break;						\
279 		}							\
280 		claimed = 0;						\
281 		MAC_CHECK(internalize_ ## type ## _label, label,	\
282 		    element_name, element_data, &claimed);		\
283 		if (error)						\
284 			break;						\
285 		if (claimed != 1) {					\
286 			/* XXXMAC: Another error here? */		\
287 			error = EINVAL;					\
288 			break;						\
289 		}							\
290 	}								\
291 } while (0)
292 
293 /*
294  * MAC_PERFORM performs the designated operation by walking the policy module
295  * list and invoking that operation for each policy.
296  */
297 #define	MAC_PERFORM(operation, args...) do {				\
298 	struct mac_policy_conf *mpc;					\
299 	int entrycount;							\
300 									\
301 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
302 		if (mpc->mpc_ops->mpo_ ## operation != NULL)		\
303 			mpc->mpc_ops->mpo_ ## operation (args);		\
304 	}								\
305 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
306 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
307 			if (mpc->mpc_ops->mpo_ ## operation != NULL)	\
308 				mpc->mpc_ops->mpo_ ## operation (args);	\
309 		}							\
310 		mac_policy_list_unbusy();				\
311 	}								\
312 } while (0)
313 
314 #endif /* !_SYS_SECURITY_MAC_MAC_INTERNAL_H_ */
315