xref: /netbsd-src/sys/secmodel/overlay/secmodel_overlay.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /* $NetBSD: secmodel_overlay.c,v 1.12 2011/12/04 19:25:00 jym Exp $ */
2 /*-
3  * Copyright (c) 2006 Elad Efrat <elad@NetBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: secmodel_overlay.c,v 1.12 2011/12/04 19:25:00 jym Exp $");
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/kauth.h>
35 #include <sys/module.h>
36 
37 #include <sys/sysctl.h>
38 
39 #include <secmodel/secmodel.h>
40 
41 #include <secmodel/overlay/overlay.h>
42 #include <secmodel/bsd44/bsd44.h>
43 #include <secmodel/suser/suser.h>
44 #include <secmodel/securelevel/securelevel.h>
45 
46 MODULE(MODULE_CLASS_SECMODEL, secmodel_overlay, "secmodel_bsd44");
47 
48 /*
49  * Fall-back settings.
50  */
51 #define	OVERLAY_ISCOPE_GENERIC	"org.netbsd.kauth.overlay.generic"
52 #define	OVERLAY_ISCOPE_SYSTEM	"org.netbsd.kauth.overlay.system"
53 #define	OVERLAY_ISCOPE_PROCESS	"org.netbsd.kauth.overlay.process"
54 #define	OVERLAY_ISCOPE_NETWORK	"org.netbsd.kauth.overlay.network"
55 #define	OVERLAY_ISCOPE_MACHDEP	"org.netbsd.kauth.overlay.machdep"
56 #define	OVERLAY_ISCOPE_DEVICE	"org.netbsd.kauth.overlay.device"
57 #define	OVERLAY_ISCOPE_VNODE	"org.netbsd.kauth.overlay.vnode"
58 
59 static kauth_scope_t secmodel_overlay_iscope_generic;
60 static kauth_scope_t secmodel_overlay_iscope_system;
61 static kauth_scope_t secmodel_overlay_iscope_process;
62 static kauth_scope_t secmodel_overlay_iscope_network;
63 static kauth_scope_t secmodel_overlay_iscope_machdep;
64 static kauth_scope_t secmodel_overlay_iscope_device;
65 static kauth_scope_t secmodel_overlay_iscope_vnode;
66 
67 static kauth_listener_t l_generic, l_system, l_process, l_network, l_machdep,
68     l_device, l_vnode;
69 
70 static secmodel_t overlay_sm;
71 static struct sysctllog *sysctl_overlay_log;
72 
73 /*
74  * Initialize the overlay security model.
75  */
76 void
77 secmodel_overlay_init(void)
78 {
79 	/*
80 	 * Register internal fall-back scopes.
81 	 */
82 	secmodel_overlay_iscope_generic = kauth_register_scope(
83 	    OVERLAY_ISCOPE_GENERIC, NULL, NULL);
84 	secmodel_overlay_iscope_system = kauth_register_scope(
85 	    OVERLAY_ISCOPE_SYSTEM, NULL, NULL);
86 	secmodel_overlay_iscope_process = kauth_register_scope(
87 	    OVERLAY_ISCOPE_PROCESS, NULL, NULL);
88 	secmodel_overlay_iscope_network = kauth_register_scope(
89 	    OVERLAY_ISCOPE_NETWORK, NULL, NULL);
90 	secmodel_overlay_iscope_machdep = kauth_register_scope(
91 	    OVERLAY_ISCOPE_MACHDEP, NULL, NULL);
92 	secmodel_overlay_iscope_device = kauth_register_scope(
93 	    OVERLAY_ISCOPE_DEVICE, NULL, NULL);
94 	secmodel_overlay_iscope_vnode = kauth_register_scope(
95 	    OVERLAY_ISCOPE_VNODE, NULL, NULL);
96 
97 	/*
98 	 * Register fall-back listeners, from suser and securelevel, to each
99 	 * internal scope.
100 	 */
101 	kauth_listen_scope(OVERLAY_ISCOPE_GENERIC,
102 	    secmodel_suser_generic_cb, NULL);
103 
104 	kauth_listen_scope(OVERLAY_ISCOPE_SYSTEM,
105 	    secmodel_suser_system_cb, NULL);
106 	kauth_listen_scope(OVERLAY_ISCOPE_SYSTEM,
107 	    secmodel_securelevel_system_cb, NULL);
108 
109 	kauth_listen_scope(OVERLAY_ISCOPE_PROCESS,
110 	    secmodel_suser_process_cb, NULL);
111 	kauth_listen_scope(OVERLAY_ISCOPE_PROCESS,
112 	    secmodel_securelevel_process_cb, NULL);
113 
114 	kauth_listen_scope(OVERLAY_ISCOPE_NETWORK,
115 	    secmodel_suser_network_cb, NULL);
116 	kauth_listen_scope(OVERLAY_ISCOPE_NETWORK,
117 	    secmodel_securelevel_network_cb, NULL);
118 
119 	kauth_listen_scope(OVERLAY_ISCOPE_MACHDEP,
120 	    secmodel_suser_machdep_cb, NULL);
121 	kauth_listen_scope(OVERLAY_ISCOPE_MACHDEP,
122 	    secmodel_securelevel_machdep_cb, NULL);
123 
124 	kauth_listen_scope(OVERLAY_ISCOPE_DEVICE,
125 	    secmodel_suser_device_cb, NULL);
126 	kauth_listen_scope(OVERLAY_ISCOPE_DEVICE,
127 	    secmodel_securelevel_device_cb, NULL);
128 }
129 
130 void
131 sysctl_security_overlay_setup(struct sysctllog **clog)
132 {
133 	const struct sysctlnode *rnode;
134 
135 	sysctl_createv(clog, 0, NULL, &rnode,
136 		       CTLFLAG_PERMANENT,
137 		       CTLTYPE_NODE, "security", NULL,
138 		       NULL, 0, NULL, 0,
139 		       CTL_SECURITY, CTL_EOL);
140 
141 	sysctl_createv(clog, 0, &rnode, &rnode,
142 		       CTLFLAG_PERMANENT,
143 		       CTLTYPE_NODE, "models", NULL,
144 		       NULL, 0, NULL, 0,
145 		       CTL_CREATE, CTL_EOL);
146 
147 	sysctl_createv(clog, 0, &rnode, &rnode,
148 		       CTLFLAG_PERMANENT,
149 		       CTLTYPE_NODE, "overlay",
150 		       SYSCTL_DESCR("Overlay security model on-top of bsd44"),
151 		       NULL, 0, NULL, 0,
152 		       CTL_CREATE, CTL_EOL);
153 
154 	sysctl_createv(clog, 0, &rnode, NULL,
155 		       CTLFLAG_PERMANENT,
156 		       CTLTYPE_STRING, "name", NULL,
157 		       NULL, 0, __UNCONST(SECMODEL_OVERLAY_NAME), 0,
158 		       CTL_CREATE, CTL_EOL);
159 }
160 
161 /*
162  * Start the overlay security model.
163  */
164 void
165 secmodel_overlay_start(void)
166 {
167 	l_generic = kauth_listen_scope(KAUTH_SCOPE_GENERIC,
168 	    secmodel_overlay_generic_cb, NULL);
169 	l_system = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
170 	    secmodel_overlay_system_cb, NULL);
171 	l_process = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
172 	    secmodel_overlay_process_cb, NULL);
173 	l_network = kauth_listen_scope(KAUTH_SCOPE_NETWORK,
174 	    secmodel_overlay_network_cb, NULL);
175 	l_machdep = kauth_listen_scope(KAUTH_SCOPE_MACHDEP,
176 	    secmodel_overlay_machdep_cb, NULL);
177 	l_device = kauth_listen_scope(KAUTH_SCOPE_DEVICE,
178 	    secmodel_overlay_device_cb, NULL);
179 	l_vnode = kauth_listen_scope(KAUTH_SCOPE_VNODE,
180 	    secmodel_overlay_vnode_cb, NULL);
181 }
182 
183 /*
184  * Stop the overlay security model.
185  */
186 void
187 secmodel_overlay_stop(void)
188 {
189 	kauth_unlisten_scope(l_generic);
190 	kauth_unlisten_scope(l_system);
191 	kauth_unlisten_scope(l_process);
192 	kauth_unlisten_scope(l_network);
193 	kauth_unlisten_scope(l_machdep);
194 	kauth_unlisten_scope(l_device);
195 	kauth_unlisten_scope(l_vnode);
196 }
197 
198 static int
199 secmodel_overlay_modcmd(modcmd_t cmd, void *arg)
200 {
201 	int error = 0;
202 
203 	switch (cmd) {
204 	case MODULE_CMD_INIT:
205 		error = secmodel_register(&overlay_sm,
206 		    SECMODEL_OVERLAY_ID, SECMODEL_OVERLAY_NAME,
207 		    NULL, NULL, NULL);
208 		if (error != 0)
209 			printf("secmodel_overlay_modcmd::init: "
210 			    "secmodel_register returned %d\n", error);
211 
212 		secmodel_overlay_init();
213 		secmodel_suser_stop();
214 		secmodel_securelevel_stop();
215 		secmodel_overlay_start();
216 		sysctl_security_overlay_setup(&sysctl_overlay_log);
217 		break;
218 
219 	case MODULE_CMD_FINI:
220 		sysctl_teardown(&sysctl_overlay_log);
221 		secmodel_overlay_stop();
222 
223 		error = secmodel_deregister(overlay_sm);
224 		if (error != 0)
225 			printf("secmodel_overlay_modcmd::fini: "
226 			    "secmodel_deregister returned %d\n", error);
227 		break;
228 
229 	case MODULE_CMD_AUTOUNLOAD:
230 		error = EPERM;
231 		break;
232 
233 	default:
234 		error = ENOTTY;
235 		break;
236 	}
237 
238 	return error;
239 }
240 
241 /*
242  * Overlay listener for the generic scope.
243  */
244 int
245 secmodel_overlay_generic_cb(kauth_cred_t cred, kauth_action_t action,
246     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
247 {
248 	int result;
249 
250 	result = KAUTH_RESULT_DEFER;
251 
252 	switch (action) {
253 	default:
254 		result = KAUTH_RESULT_DEFER;
255 		break;
256 	}
257 
258 	if (result == KAUTH_RESULT_DEFER) {
259 		result = kauth_authorize_action(
260 		    secmodel_overlay_iscope_generic, cred, action,
261 		    arg0, arg1, arg2, arg3);
262 	}
263 
264 	return (result);
265 }
266 
267 /*
268  * Overlay listener for the system scope.
269  */
270 int
271 secmodel_overlay_system_cb(kauth_cred_t cred, kauth_action_t action,
272     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
273 {
274 	int result;
275 
276 	result = KAUTH_RESULT_DEFER;
277 
278 	switch (action) {
279 	default:
280 		result = KAUTH_RESULT_DEFER;
281 		break;
282 	}
283 
284 	if (result == KAUTH_RESULT_DEFER) {
285 		result = kauth_authorize_action(
286 		    secmodel_overlay_iscope_system, cred, action,
287 		    arg0, arg1, arg2, arg3);
288 	}
289 
290 	return (result);
291 }
292 
293 /*
294  * Overlay listener for the process scope.
295  */
296 int
297 secmodel_overlay_process_cb(kauth_cred_t cred, kauth_action_t action,
298     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
299 {
300 	int result;
301 
302 	result = KAUTH_RESULT_DEFER;
303 
304 	switch (action) {
305 	default:
306 		result = KAUTH_RESULT_DEFER;
307 		break;
308 	}
309 
310 	if (result == KAUTH_RESULT_DEFER) {
311 		result = kauth_authorize_action(
312 		    secmodel_overlay_iscope_process, cred, action,
313 		    arg0, arg1, arg2, arg3);
314 	}
315 
316 	return (result);
317 }
318 
319 /*
320  * Overlay listener for the network scope.
321  */
322 int
323 secmodel_overlay_network_cb(kauth_cred_t cred, kauth_action_t action,
324     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
325 {
326 	int result;
327 
328 	result = KAUTH_RESULT_DEFER;
329 
330 	switch (action) {
331 	default:
332 		result = KAUTH_RESULT_DEFER;
333 		break;
334 	}
335 
336 	if (result == KAUTH_RESULT_DEFER) {
337 		result = kauth_authorize_action(
338 		    secmodel_overlay_iscope_network, cred, action,
339 		    arg0, arg1, arg2, arg3);
340 	}
341 
342 	return (result);
343 }
344 
345 /*
346  * Overlay listener for the machdep scope.
347  */
348 int
349 secmodel_overlay_machdep_cb(kauth_cred_t cred, kauth_action_t action,
350     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
351 {
352 	int result;
353 
354 	result = KAUTH_RESULT_DEFER;
355 
356 	switch (action) {
357 	default:
358 		result = KAUTH_RESULT_DEFER;
359 		break;
360 	}
361 
362 	if (result == KAUTH_RESULT_DEFER) {
363 		result = kauth_authorize_action(
364 		    secmodel_overlay_iscope_machdep, cred, action,
365 		    arg0, arg1, arg2, arg3);
366 	}
367 
368 	return (result);
369 }
370 
371 /*
372  * Overlay listener for the device scope.
373  */
374 int
375 secmodel_overlay_device_cb(kauth_cred_t cred, kauth_action_t action,
376     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
377 {
378 	int result;
379 
380 	result = KAUTH_RESULT_DEFER;
381 
382 	switch (action) {
383 	default:
384 		result = KAUTH_RESULT_DEFER;
385 		break;
386 	}
387 
388 	if (result == KAUTH_RESULT_DEFER) {
389 		result = kauth_authorize_action(
390 		    secmodel_overlay_iscope_device, cred, action,
391 		    arg0, arg1, arg2, arg3);
392 	}
393 
394 	return (result);
395 }
396 
397 /*
398  * Overlay listener for the vnode scope.
399  */
400 int
401 secmodel_overlay_vnode_cb(kauth_cred_t cred, kauth_action_t action,
402     void *cookie, void *arg0, void *arg1, void *arg2, void *arg3)
403 {
404 	int result;
405 
406 	result = KAUTH_RESULT_DEFER;
407 
408 	switch (action) {
409 	default:
410 		result = KAUTH_RESULT_DEFER;
411 		break;
412 	}
413 
414 	if (result == KAUTH_RESULT_DEFER) {
415 		result = kauth_authorize_action(
416 		    secmodel_overlay_iscope_vnode, cred, action,
417 		    arg0, arg1, arg2, arg3);
418 	}
419 
420 	return (result);
421 }
422