xref: /xnu-11215/security/mac_internal.h (revision 8d741a5d)
1 /*
2  * Copyright (c) 2007 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 /*-
30  * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
31  * Copyright (c) 2001 Ilmar S. Habibulin
32  * Copyright (c) 2001, 2002, 2003, 2004 Networks Associates Technology, Inc.
33  * Copyright (c) 2005 SPARTA, Inc.
34  * All rights reserved.
35  *
36  * This software was developed by Robert Watson and Ilmar Habibulin for the
37  * TrustedBSD Project.
38  *
39  * This software was developed for the FreeBSD Project in part by Network
40  * Associates Laboratories, the Security Research Division of Network
41  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
42  * as part of the DARPA CHATS research program.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  */
66 
67 #ifndef _SECURITY_MAC_INTERNAL_H_
68 #define _SECURITY_MAC_INTERNAL_H_
69 
70 #ifndef PRIVATE
71 #warning "MAC policy is not KPI, see Technical Q&A QA1574, this header will be removed in next version"
72 #endif
73 
74 #include <string.h>
75 #include <sys/param.h>
76 #include <sys/queue.h>
77 #include <security/mac.h>
78 #include <security/mac_framework.h>
79 #include <security/mac_policy.h>
80 #include <security/mac_data.h>
81 #include <sys/sysctl.h>
82 #include <kern/locks.h>
83 #include <sys/kernel.h>
84 #include <sys/lock.h>
85 #include <sys/malloc.h>
86 #include <sys/sbuf.h>
87 #include <sys/proc.h>
88 #include <sys/systm.h>
89 #include <sys/socket.h>
90 #include <sys/socketvar.h>
91 #include <sys/vnode.h>
92 #include <mach/sdt.h>
93 
94 /*
95  * MAC Framework sysctl namespace.
96  */
97 
98 SYSCTL_DECL(_security);
99 SYSCTL_DECL(_security_mac);
100 
101 extern int mac_late;
102 
103 struct mac_policy_list_element {
104 	struct mac_policy_conf *mpc;
105 };
106 
107 struct mac_policy_list {
108 	u_int                           numloaded;
109 	u_int                           max;
110 	u_int                           maxindex;
111 	u_int                           staticmax;
112 	u_int                           chunks;
113 	u_int                           freehint;
114 	struct mac_policy_list_element  *entries;
115 };
116 
117 typedef struct mac_policy_list mac_policy_list_t;
118 
119 
120 /*
121  * Policy that has registered with the framework for a specific
122  * label namespace name.
123  */
124 struct mac_label_listener {
125 	mac_policy_handle_t             mll_handle;
126 	SLIST_ENTRY(mac_label_listener) mll_list;
127 };
128 
129 SLIST_HEAD(mac_label_listeners_t, mac_label_listener);
130 
131 /*
132  * Type of list used to manage label namespace names.
133  */
134 struct mac_label_element {
135 	char                            mle_name[MAC_MAX_LABEL_ELEMENT_NAME];
136 	struct mac_label_listeners_t    mle_listeners;
137 	SLIST_ENTRY(mac_label_element)  mle_list;
138 };
139 
140 SLIST_HEAD(mac_label_element_list_t, mac_label_element);
141 
142 /*
143  * MAC Framework global variables.
144  */
145 
146 extern struct mac_label_element_list_t mac_label_element_list;
147 extern struct mac_label_element_list_t mac_static_label_element_list;
148 
149 extern struct mac_policy_list mac_policy_list;
150 
151 /*
152  * global flags to control whether a MACF subsystem is configured
153  * at all in the system.
154  */
155 extern unsigned int mac_device_enforce;
156 extern unsigned int mac_pipe_enforce;
157 extern unsigned int mac_posixsem_enforce;
158 extern unsigned int mac_posixshm_enforce;
159 extern unsigned int mac_proc_enforce;
160 extern unsigned int mac_socket_enforce;
161 extern unsigned int mac_system_enforce;
162 extern unsigned int mac_sysvmsg_enforce;
163 extern unsigned int mac_sysvsem_enforce;
164 extern unsigned int mac_sysvshm_enforce;
165 extern unsigned int mac_vm_enforce;
166 extern unsigned int mac_vnode_enforce;
167 
168 extern unsigned int mac_label_vnodes;
169 extern unsigned int mac_vnode_label_count;
170 
171 static bool mac_proc_check_enforce(proc_t p);
172 
173 static __inline__ bool
mac_proc_check_enforce(proc_t p)174 mac_proc_check_enforce(proc_t p)
175 {
176 #if CONFIG_MACF
177 	// Don't apply policies to the kernel itself.
178 	return p != kernproc;
179 #else
180 #pragma unused(p)
181 	return false;
182 #endif // CONFIG_MACF
183 }
184 
185 static bool mac_cred_check_enforce(kauth_cred_t cred);
186 
187 static __inline__ bool
mac_cred_check_enforce(kauth_cred_t cred)188 mac_cred_check_enforce(kauth_cred_t cred)
189 {
190 #if CONFIG_MACF
191 	return cred != proc_ucred_unsafe(kernproc);
192 #else
193 #pragma unused(p)
194 	return false;
195 #endif // CONFIG_MACF
196 }
197 
198 /*
199  * MAC Framework infrastructure functions.
200  */
201 
202 int mac_error_select(int error1, int error2);
203 
204 void  mac_policy_list_busy(void);
205 int   mac_policy_list_conditional_busy(void);
206 void  mac_policy_list_unbusy(void);
207 
208 #if KERNEL
209 int   mac_check_structmac_consistent(struct user_mac *mac);
210 #else
211 int   mac_check_structmac_consistent(struct mac *mac);
212 #endif
213 
214 int mac_cred_label_externalize(struct label *, char *e, char *out, size_t olen, int flags);
215 int mac_vnode_label_externalize(struct label *, char *e, char *out, size_t olen, int flags);
216 
217 int mac_cred_label_internalize(struct label *label, char *string);
218 int mac_vnode_label_internalize(struct label *label, char *string);
219 
220 typedef int (^mac_getter_t)(char *, char *, size_t);
221 typedef int (^mac_setter_t)(char *, size_t);
222 
223 int mac_do_get(struct proc *p, user_addr_t mac_p, mac_getter_t getter);
224 int mac_do_set(struct proc *p, user_addr_t mac_p, mac_setter_t setter);
225 
226 #define MAC_POLICY_ITERATE(...) do {                                \
227     struct mac_policy_conf *mpc;                                    \
228     u_int i;                                                        \
229                                                                     \
230     for (i = 0; i < mac_policy_list.staticmax; i++) {               \
231 	    mpc = mac_policy_list.entries[i].mpc;                       \
232 	    if (mpc == NULL)                                            \
233 	            continue;                                           \
234                                                                     \
235 	    __VA_ARGS__                                                 \
236     }                                                               \
237     if (mac_policy_list_conditional_busy() != 0) {                  \
238 	    for (; i <= mac_policy_list.maxindex; i++) {                \
239 	            mpc = mac_policy_list.entries[i].mpc;               \
240 	            if (mpc == NULL)                                    \
241 	                    continue;                                   \
242                                                                     \
243 	            __VA_ARGS__                                         \
244 	    }                                                           \
245 	    mac_policy_list_unbusy();                                   \
246     }                                                               \
247 } while (0)
248 
249 enum mac_iterate_types {
250 	MAC_ITERATE_CHECK = 0,  // error starts at 0, callbacks can change it
251 	MAC_ITERATE_GRANT = 1,  // error starts as EPERM, callbacks can clear it
252 	MAC_ITERATE_PERFORM = 2, // no result
253 };
254 
255 #define MAC_CHECK_CALL(check, mpc) DTRACE_MACF3(mac__call__ ## check, void *, mpc, int, error, int, MAC_ITERATE_CHECK)
256 #define MAC_CHECK_RSLT(check, mpc) DTRACE_MACF2(mac__rslt__ ## check, void *, mpc, int, __step_err)
257 
258 /*
259  * MAC_CHECK performs the designated check by walking the policy
260  * module list and checking with each as to how it feels about the
261  * request.  Note that it returns its value via 'error' in the scope
262  * of the caller.
263  */
264 #define MAC_CHECK(check, args...) do {                                   \
265     error = 0;                                                           \
266     MAC_POLICY_ITERATE({                                                 \
267 	    if (mpc->mpc_ops->mpo_ ## check != NULL) {                   \
268 	            MAC_CHECK_CALL(check, mpc);                          \
269 	            int __step_err = mpc->mpc_ops->mpo_ ## check (args); \
270 	            MAC_CHECK_RSLT(check, mpc);                          \
271 	            error = mac_error_select(__step_err, error);         \
272 	    }                                                            \
273     });                                                                  \
274 } while (0)
275 
276 /*
277  * MAC_GRANT performs the designated check by walking the policy
278  * module list and checking with each as to how it feels about the
279  * request.  Unlike MAC_CHECK, it grants if any policies return '0',
280  * and otherwise returns EPERM.  Note that it returns its value via
281  * 'error' in the scope of the caller.
282  */
283 #define MAC_GRANT(check, args...) do {                              \
284     error = EPERM;                                                  \
285     MAC_POLICY_ITERATE({                                            \
286 	if (mpc->mpc_ops->mpo_ ## check != NULL) {                  \
287 	        DTRACE_MACF3(mac__call__ ## check, void *, mpc, int, error, int, MAC_ITERATE_GRANT); \
288 	        int __step_res = mpc->mpc_ops->mpo_ ## check (args); \
289 	        if (__step_res == 0) {                              \
290 	                error = 0;                                  \
291 	        }                                                   \
292 	        DTRACE_MACF2(mac__rslt__ ## check, void *, mpc, int, __step_res); \
293 	    }                                                           \
294     });                                                             \
295 } while (0)
296 
297 #define MAC_INTERNALIZE(obj, label, instring)                       \
298     mac_internalize(offsetof(struct mac_policy_ops, mpo_ ## obj ## _label_internalize), label, instring)
299 
300 #define MAC_EXTERNALIZE(obj, label, elementlist, outbuf, outbuflen) \
301     mac_externalize(offsetof(struct mac_policy_ops, mpo_ ## obj ## _label_externalize), label, elementlist, outbuf, outbuflen)
302 
303 #define MAC_EXTERNALIZE_AUDIT(obj, label, outbuf, outbuflen)        \
304     mac_externalize(offsetof(struct mac_policy_ops, mpo_ ## obj ## _label_externalize_audit), label, "*", outbuf, outbuflen)
305 
306 #define MAC_PERFORM_CALL(operation, mpc) DTRACE_MACF3(mac__call__ ## operation, void *, mpc, int, 0, int, MAC_ITERATE_PERFORM)
307 #define MAC_PERFORM_RSLT(operation, mpc) DTRACE_MACF2(mac__rslt__ ## operation, void *, mpc, int, 0)
308 
309 /*
310  * MAC_PERFORM performs the designated operation by walking the policy
311  * module list and invoking that operation for each policy.
312  */
313 #define MAC_PERFORM(operation, args...) do {                \
314     MAC_POLICY_ITERATE({                                    \
315 	if (mpc->mpc_ops->mpo_ ## operation != NULL) {      \
316 	        MAC_PERFORM_CALL(operation, mpc);           \
317 	        mpc->mpc_ops->mpo_ ## operation (args);     \
318 	        MAC_PERFORM_RSLT(operation, mpc);           \
319 	}                                                   \
320     });                                                     \
321 } while (0)
322 
323 
324 #
325 struct __mac_get_pid_args;
326 struct __mac_get_proc_args;
327 struct __mac_set_proc_args;
328 struct __mac_get_lcid_args;
329 struct __mac_get_fd_args;
330 struct __mac_get_file_args;
331 struct __mac_get_link_args;
332 struct __mac_set_fd_args;
333 struct __mac_set_file_args;
334 struct __mac_syscall_args;
335 
336 void mac_policy_addto_labellist(const mac_policy_handle_t, int);
337 void mac_policy_removefrom_labellist(const mac_policy_handle_t);
338 
339 int mac_externalize(size_t mpo_externalize_off, struct label *label,
340     const char *elementlist, char *outbuf, size_t outbuflen);
341 int mac_internalize(size_t mpo_internalize_off, struct label *label,
342     char *elementlist);
343 #endif  /* !_SECURITY_MAC_INTERNAL_H_ */
344