xref: /freebsd/sys/security/mac/mac_internal.h (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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  * All rights reserved.
6  *
7  * This software was developed by Robert Watson and Ilmar Habibulin for the
8  * TrustedBSD Project.
9  *
10  * This software was developed for the FreeBSD Project in part by Network
11  * Associates Laboratories, the Security Research Division of Network
12  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
13  * as part of the DARPA CHATS research program.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * $FreeBSD$
37  */
38 
39 /*
40  * MAC Framework sysctl namespace.
41  */
42 #ifdef SYSCTL_DECL
43 SYSCTL_DECL(_security);
44 SYSCTL_DECL(_security_mac);
45 #ifdef MAC_DEBUG
46 SYSCTL_DECL(_security_mac_debug);
47 SYSCTL_DECL(_security_mac_debug_counters);
48 #endif
49 #endif /* SYSCTL_DECL */
50 
51 /*
52  * MAC Framework global types and typedefs.
53  */
54 LIST_HEAD(mac_policy_list_head, mac_policy_conf);
55 #ifdef MALLOC_DECLARE
56 MALLOC_DECLARE(M_MACTEMP);
57 #endif
58 
59 /*
60  * MAC Framework global variables.
61  */
62 extern struct mac_policy_list_head	mac_policy_list;
63 extern struct mac_policy_list_head	mac_static_policy_list;
64 extern int				mac_late;
65 extern int				mac_enforce_network;
66 extern int				mac_enforce_process;
67 extern int				mac_enforce_socket;
68 extern int				mac_enforce_vm;
69 #ifndef MAC_ALWAYS_LABEL_MBUF
70 extern int				mac_labelmbufs;
71 #endif
72 
73 /*
74  * MAC Framework object/access counter primitives, conditionally
75  * compiled.
76  */
77 #ifdef MAC_DEBUG
78 #define	MAC_DEBUG_COUNTER_INC(x)	atomic_add_int(x, 1);
79 #define	MAC_DEBUG_COUNTER_DEC(x)	atomic_subtract_int(x, 1);
80 #else
81 #define	MAC_DEBUG_COUNTER_INC(x)
82 #define	MAC_DEBUG_COUNTER_DEC(x)
83 #endif
84 
85 /*
86  * MAC Framework infrastructure functions.
87  */
88 int	mac_error_select(int error1, int error2);
89 
90 void	mac_policy_grab_exclusive(void);
91 void	mac_policy_assert_exclusive(void);
92 void	mac_policy_release_exclusive(void);
93 void	mac_policy_list_busy(void);
94 int	mac_policy_list_conditional_busy(void);
95 void	mac_policy_list_unbusy(void);
96 
97 struct label	*mac_labelzone_alloc(int flags);
98 void		 mac_labelzone_free(struct label *label);
99 void		 mac_labelzone_init(void);
100 
101 void	mac_init_label(struct label *label);
102 void	mac_destroy_label(struct label *label);
103 int	mac_check_structmac_consistent(struct mac *mac);
104 int	mac_allocate_slot(void);
105 
106 /*
107  * MAC Framework per-object type functions.  It's not yet clear how
108  * the namespaces, etc, should work for these, so for now, sort by
109  * object type.
110  */
111 struct label	*mac_pipe_label_alloc(void);
112 void		 mac_pipe_label_free(struct label *label);
113 struct label	*mac_socket_label_alloc(int flag);
114 void		 mac_socket_label_free(struct label *label);
115 
116 int	mac_check_cred_relabel(struct ucred *cred, struct label *newlabel);
117 int	mac_externalize_cred_label(struct label *label, char *elements,
118 	    char *outbuf, size_t outbuflen);
119 int	mac_internalize_cred_label(struct label *label, char *string);
120 void	mac_relabel_cred(struct ucred *cred, struct label *newlabel);
121 
122 struct label	*mac_mbuf_to_label(struct mbuf *m);
123 
124 void	mac_copy_pipe_label(struct label *src, struct label *dest);
125 int	mac_externalize_pipe_label(struct label *label, char *elements,
126 	    char *outbuf, size_t outbuflen);
127 int	mac_internalize_pipe_label(struct label *label, char *string);
128 
129 int	mac_socket_label_set(struct ucred *cred, struct socket *so,
130 	    struct label *label);
131 void	mac_copy_socket_label(struct label *src, struct label *dest);
132 int	mac_externalize_socket_label(struct label *label, char *elements,
133 	    char *outbuf, size_t outbuflen);
134 int	mac_internalize_socket_label(struct label *label, char *string);
135 
136 int	mac_externalize_vnode_label(struct label *label, char *elements,
137 	    char *outbuf, size_t outbuflen);
138 int	mac_internalize_vnode_label(struct label *label, char *string);
139 void	mac_check_vnode_mmap_downgrade(struct ucred *cred, struct vnode *vp,
140 	    int *prot);
141 int	vn_setlabel(struct vnode *vp, struct label *intlabel,
142 	    struct ucred *cred);
143 
144 /*
145  * MAC_CHECK performs the designated check by walking the policy module
146  * list and checking with each as to how it feels about the request.
147  * Note that it returns its value via 'error' in the scope of the caller.
148  */
149 #define	MAC_CHECK(check, args...) do {					\
150 	struct mac_policy_conf *mpc;					\
151 	int entrycount;							\
152 									\
153 	error = 0;							\
154 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
155 		if (mpc->mpc_ops->mpo_ ## check != NULL)		\
156 			error = mac_error_select(			\
157 			    mpc->mpc_ops->mpo_ ## check (args),		\
158 			    error);					\
159 	}								\
160 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
161 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
162 			if (mpc->mpc_ops->mpo_ ## check != NULL)	\
163 				error = mac_error_select(		\
164 				    mpc->mpc_ops->mpo_ ## check (args),	\
165 				    error);				\
166 		}							\
167 		mac_policy_list_unbusy();				\
168 	}								\
169 } while (0)
170 
171 /*
172  * MAC_BOOLEAN performs the designated boolean composition by walking
173  * the module list, invoking each instance of the operation, and
174  * combining the results using the passed C operator.  Note that it
175  * returns its value via 'result' in the scope of the caller, which
176  * should be initialized by the caller in a meaningful way to get
177  * a meaningful result.
178  */
179 #define	MAC_BOOLEAN(operation, composition, args...) do {		\
180 	struct mac_policy_conf *mpc;					\
181 	int entrycount;							\
182 									\
183 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
184 		if (mpc->mpc_ops->mpo_ ## operation != NULL)		\
185 			result = result composition			\
186 			    mpc->mpc_ops->mpo_ ## operation (args);	\
187 	}								\
188 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
189 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
190 			if (mpc->mpc_ops->mpo_ ## operation != NULL)	\
191 				result = result composition		\
192 				    mpc->mpc_ops->mpo_ ## operation	\
193 				    (args);				\
194 		}							\
195 		mac_policy_list_unbusy();				\
196 	}								\
197 } while (0)
198 
199 #define	MAC_EXTERNALIZE(type, label, elementlist, outbuf, 		\
200     outbuflen) do {							\
201 	int claimed, first, ignorenotfound, savedlen;			\
202 	char *element_name, *element_temp;				\
203 	struct sbuf sb;							\
204 									\
205 	error = 0;							\
206 	first = 1;							\
207 	sbuf_new(&sb, outbuf, outbuflen, SBUF_FIXEDLEN);		\
208 	element_temp = elementlist;					\
209 	while ((element_name = strsep(&element_temp, ",")) != NULL) {	\
210 		if (element_name[0] == '?') {				\
211 			element_name++;					\
212 			ignorenotfound = 1;				\
213 		 } else							\
214 			ignorenotfound = 0;				\
215 		savedlen = sbuf_len(&sb);				\
216 		if (first)						\
217 			error = sbuf_printf(&sb, "%s/", element_name);	\
218 		else							\
219 			error = sbuf_printf(&sb, ",%s/", element_name);	\
220 		if (error == -1) {					\
221 			error = EINVAL;	/* XXX: E2BIG? */		\
222 			break;						\
223 		}							\
224 		claimed = 0;						\
225 		MAC_CHECK(externalize_ ## type ## _label, label,	\
226 		    element_name, &sb, &claimed);			\
227 		if (error)						\
228 			break;						\
229 		if (claimed == 0 && ignorenotfound) {			\
230 			/* Revert last label name. */			\
231 			sbuf_setpos(&sb, savedlen);			\
232 		} else if (claimed != 1) {				\
233 			error = EINVAL;	/* XXX: ENOLABEL? */		\
234 			break;						\
235 		} else {						\
236 			first = 0;					\
237 		}							\
238 	}								\
239 	sbuf_finish(&sb);						\
240 } while (0)
241 
242 #define	MAC_INTERNALIZE(type, label, instring) do {			\
243 	char *element, *element_name, *element_data;			\
244 	int claimed;							\
245 									\
246 	error = 0;							\
247 	element = instring;						\
248 	while ((element_name = strsep(&element, ",")) != NULL) {	\
249 		element_data = element_name;				\
250 		element_name = strsep(&element_data, "/");		\
251 		if (element_data == NULL) {				\
252 			error = EINVAL;					\
253 			break;						\
254 		}							\
255 		claimed = 0;						\
256 		MAC_CHECK(internalize_ ## type ## _label, label,	\
257 		    element_name, element_data, &claimed);		\
258 		if (error)						\
259 			break;						\
260 		if (claimed != 1) {					\
261 			/* XXXMAC: Another error here? */		\
262 			error = EINVAL;					\
263 			break;						\
264 		}							\
265 	}								\
266 } while (0)
267 
268 /*
269  * MAC_PERFORM performs the designated operation by walking the policy
270  * module list and invoking that operation for each policy.
271  */
272 #define	MAC_PERFORM(operation, args...) do {				\
273 	struct mac_policy_conf *mpc;					\
274 	int entrycount;							\
275 									\
276 	LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {		\
277 		if (mpc->mpc_ops->mpo_ ## operation != NULL)		\
278 			mpc->mpc_ops->mpo_ ## operation (args);		\
279 	}								\
280 	if ((entrycount = mac_policy_list_conditional_busy()) != 0) {	\
281 		LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {		\
282 			if (mpc->mpc_ops->mpo_ ## operation != NULL)	\
283 				mpc->mpc_ops->mpo_ ## operation (args);	\
284 		}							\
285 		mac_policy_list_unbusy();				\
286 	}								\
287 } while (0)
288