xref: /netbsd-src/sys/kern/kern_auth.c (revision c0179c282a5968435315a82f4128c61372c68fc3)
1 /* $NetBSD: kern_auth.c,v 1.32 2006/11/19 00:11:29 elad Exp $ */
2 
3 /*-
4  * Copyright (c) 2005, 2006 Elad Efrat <elad@NetBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Elad Efrat.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: kern_auth.c,v 1.32 2006/11/19 00:11:29 elad Exp $");
35 
36 #include <sys/types.h>
37 #include <sys/param.h>
38 #include <sys/queue.h>
39 #include <sys/time.h>
40 #include <sys/proc.h>
41 #include <sys/ucred.h>
42 #include <sys/pool.h>
43 #include <sys/kauth.h>
44 #include <sys/acct.h>
45 #include <sys/sysctl.h>
46 
47 /*
48  * Credentials.
49  */
50 struct kauth_cred {
51 	struct simplelock cr_lock;	/* lock on cr_refcnt */
52 	u_int cr_refcnt;		/* reference count */
53 	uid_t cr_uid;			/* user id */
54 	uid_t cr_euid;			/* effective user id */
55 	uid_t cr_svuid;			/* saved effective user id */
56 	gid_t cr_gid;			/* group id */
57 	gid_t cr_egid;			/* effective group id */
58 	gid_t cr_svgid;			/* saved effective group id */
59 	u_int cr_ngroups;		/* number of groups */
60 	gid_t cr_groups[NGROUPS];	/* group memberships */
61 };
62 
63 /*
64  * Listener.
65  */
66 struct kauth_listener {
67 	kauth_scope_callback_t		func;		/* callback */
68 	kauth_scope_t			scope;		/* scope backpointer */
69 	u_int				refcnt;		/* reference count */
70 	SIMPLEQ_ENTRY(kauth_listener)	listener_next;	/* listener list */
71 };
72 
73 /*
74  * Scope.
75  */
76 struct kauth_scope {
77 	const char		       *id;		/* scope name */
78 	void			       *cookie;		/* user cookie */
79 	u_int				nlisteners;	/* # of listeners */
80 	SIMPLEQ_HEAD(, kauth_listener)	listenq;	/* listener list */
81 	SIMPLEQ_ENTRY(kauth_scope)	next_scope;	/* scope list */
82 };
83 
84 static POOL_INIT(kauth_scope_pool, sizeof(struct kauth_scope), 0, 0, 0,
85 	  "kauth_scopepl", &pool_allocator_nointr);
86 static POOL_INIT(kauth_listener_pool, sizeof(struct kauth_listener), 0, 0, 0,
87 	  "kauth_listenerpl", &pool_allocator_nointr);
88 static POOL_INIT(kauth_cred_pool, sizeof(struct kauth_cred), 0, 0, 0,
89 	  "kauth_credpl", &pool_allocator_nointr);
90 
91 /* List of scopes and its lock. */
92 static SIMPLEQ_HEAD(, kauth_scope) scope_list;
93 static struct simplelock scopes_lock;
94 
95 /* Built-in scopes: generic, process. */
96 static kauth_scope_t kauth_builtin_scope_generic;
97 static kauth_scope_t kauth_builtin_scope_system;
98 static kauth_scope_t kauth_builtin_scope_process;
99 static kauth_scope_t kauth_builtin_scope_network;
100 static kauth_scope_t kauth_builtin_scope_machdep;
101 static kauth_scope_t kauth_builtin_scope_device;
102 
103 static boolean_t listeners_have_been_loaded = FALSE;
104 
105 /* Allocate new, empty kauth credentials. */
106 kauth_cred_t
107 kauth_cred_alloc(void)
108 {
109 	kauth_cred_t cred;
110 
111 	cred = pool_get(&kauth_cred_pool, PR_WAITOK);
112 	memset(cred, 0, sizeof(*cred));
113 	simple_lock_init(&cred->cr_lock);
114 	cred->cr_refcnt = 1;
115 
116 	return (cred);
117 }
118 
119 /* Increment reference count to cred. */
120 void
121 kauth_cred_hold(kauth_cred_t cred)
122 {
123 	KASSERT(cred != NULL);
124 	KASSERT(cred->cr_refcnt > 0);
125 
126         simple_lock(&cred->cr_lock);
127         cred->cr_refcnt++;
128         simple_unlock(&cred->cr_lock);
129 }
130 
131 /* Decrease reference count to cred. If reached zero, free it. */
132 void
133 kauth_cred_free(kauth_cred_t cred)
134 {
135 	u_int refcnt;
136 
137 	KASSERT(cred != NULL);
138 	KASSERT(cred->cr_refcnt > 0);
139 
140 	simple_lock(&cred->cr_lock);
141 	refcnt = --cred->cr_refcnt;
142 	simple_unlock(&cred->cr_lock);
143 
144 	if (refcnt == 0)
145 		pool_put(&kauth_cred_pool, cred);
146 }
147 
148 void
149 kauth_cred_clone(kauth_cred_t from, kauth_cred_t to)
150 {
151 	KASSERT(from != NULL);
152 	KASSERT(to != NULL);
153 	KASSERT(from->cr_refcnt > 0);
154 
155 	to->cr_uid = from->cr_uid;
156 	to->cr_euid = from->cr_euid;
157 	to->cr_svuid = from->cr_svuid;
158 	to->cr_gid = from->cr_gid;
159 	to->cr_egid = from->cr_egid;
160 	to->cr_svgid = from->cr_svgid;
161 	to->cr_ngroups = from->cr_ngroups;
162 	memcpy(to->cr_groups, from->cr_groups, sizeof(to->cr_groups));
163 }
164 
165 /*
166  * Duplicate cred and return a new kauth_cred_t.
167  */
168 kauth_cred_t
169 kauth_cred_dup(kauth_cred_t cred)
170 {
171 	kauth_cred_t new_cred;
172 
173 	KASSERT(cred != NULL);
174 	KASSERT(cred->cr_refcnt > 0);
175 
176 	new_cred = kauth_cred_alloc();
177 
178 	kauth_cred_clone(cred, new_cred);
179 
180 	return (new_cred);
181 }
182 
183 /*
184  * Similar to crcopy(), only on a kauth_cred_t.
185  * XXX: Is this even needed? [kauth_cred_copy]
186  */
187 kauth_cred_t
188 kauth_cred_copy(kauth_cred_t cred)
189 {
190 	kauth_cred_t new_cred;
191 
192 	KASSERT(cred != NULL);
193 	KASSERT(cred->cr_refcnt > 0);
194 
195 	/* If the provided credentials already have one reference, use them. */
196 	if (cred->cr_refcnt == 1)
197 		return (cred);
198 
199 	new_cred = kauth_cred_alloc();
200 
201 	kauth_cred_clone(cred, new_cred);
202 
203 	kauth_cred_free(cred);
204 
205 	return (new_cred);
206 }
207 
208 uid_t
209 kauth_cred_getuid(kauth_cred_t cred)
210 {
211 	KASSERT(cred != NULL);
212 
213 	return (cred->cr_uid);
214 }
215 
216 uid_t
217 kauth_cred_geteuid(kauth_cred_t cred)
218 {
219 	KASSERT(cred != NULL);
220 
221 	return (cred->cr_euid);
222 }
223 
224 uid_t
225 kauth_cred_getsvuid(kauth_cred_t cred)
226 {
227 	KASSERT(cred != NULL);
228 
229 	return (cred->cr_svuid);
230 }
231 
232 gid_t
233 kauth_cred_getgid(kauth_cred_t cred)
234 {
235 	KASSERT(cred != NULL);
236 
237 	return (cred->cr_gid);
238 }
239 
240 gid_t
241 kauth_cred_getegid(kauth_cred_t cred)
242 {
243 	KASSERT(cred != NULL);
244 
245 	return (cred->cr_egid);
246 }
247 
248 gid_t
249 kauth_cred_getsvgid(kauth_cred_t cred)
250 {
251 	KASSERT(cred != NULL);
252 
253 	return (cred->cr_svgid);
254 }
255 
256 void
257 kauth_cred_setuid(kauth_cred_t cred, uid_t uid)
258 {
259 	KASSERT(cred != NULL);
260 	KASSERT(cred->cr_refcnt == 1);
261 
262 	cred->cr_uid = uid;
263 }
264 
265 void
266 kauth_cred_seteuid(kauth_cred_t cred, uid_t uid)
267 {
268 	KASSERT(cred != NULL);
269 	KASSERT(cred->cr_refcnt == 1);
270 
271 	cred->cr_euid = uid;
272 }
273 
274 void
275 kauth_cred_setsvuid(kauth_cred_t cred, uid_t uid)
276 {
277 	KASSERT(cred != NULL);
278 	KASSERT(cred->cr_refcnt == 1);
279 
280 	cred->cr_svuid = uid;
281 }
282 
283 void
284 kauth_cred_setgid(kauth_cred_t cred, gid_t gid)
285 {
286 	KASSERT(cred != NULL);
287 	KASSERT(cred->cr_refcnt == 1);
288 
289 	cred->cr_gid = gid;
290 }
291 
292 void
293 kauth_cred_setegid(kauth_cred_t cred, gid_t gid)
294 {
295 	KASSERT(cred != NULL);
296 	KASSERT(cred->cr_refcnt == 1);
297 
298 	cred->cr_egid = gid;
299 }
300 
301 void
302 kauth_cred_setsvgid(kauth_cred_t cred, gid_t gid)
303 {
304 	KASSERT(cred != NULL);
305 	KASSERT(cred->cr_refcnt == 1);
306 
307 	cred->cr_svgid = gid;
308 }
309 
310 /* Checks if gid is a member of the groups in cred. */
311 int
312 kauth_cred_ismember_gid(kauth_cred_t cred, gid_t gid, int *resultp)
313 {
314 	int i;
315 
316 	KASSERT(cred != NULL);
317 	KASSERT(resultp != NULL);
318 
319 	*resultp = 0;
320 
321 	for (i = 0; i < cred->cr_ngroups; i++)
322 		if (cred->cr_groups[i] == gid) {
323 			*resultp = 1;
324 			break;
325 		}
326 
327 	return (0);
328 }
329 
330 u_int
331 kauth_cred_ngroups(kauth_cred_t cred)
332 {
333 	KASSERT(cred != NULL);
334 
335 	return (cred->cr_ngroups);
336 }
337 
338 /*
339  * Return the group at index idx from the groups in cred.
340  */
341 gid_t
342 kauth_cred_group(kauth_cred_t cred, u_int idx)
343 {
344 	KASSERT(cred != NULL);
345 	KASSERT(idx < cred->cr_ngroups);
346 
347 	return (cred->cr_groups[idx]);
348 }
349 
350 /* XXX elad: gmuid is unused for now. */
351 int
352 kauth_cred_setgroups(kauth_cred_t cred, gid_t *grbuf, size_t len, uid_t gmuid)
353 {
354 	KASSERT(cred != NULL);
355 	KASSERT(cred->cr_refcnt == 1);
356 	KASSERT(len <= sizeof(cred->cr_groups) / sizeof(cred->cr_groups[0]));
357 
358 	if (len)
359 		memcpy(cred->cr_groups, grbuf, len * sizeof(cred->cr_groups[0]));
360 	memset(cred->cr_groups + len, 0xff,
361 	    sizeof(cred->cr_groups) - (len * sizeof(cred->cr_groups[0])));
362 
363 	cred->cr_ngroups = len;
364 
365 	return (0);
366 }
367 
368 int
369 kauth_cred_getgroups(kauth_cred_t cred, gid_t *grbuf, size_t len)
370 {
371 	KASSERT(cred != NULL);
372 	KASSERT(len <= cred->cr_ngroups);
373 
374 	memset(grbuf, 0xff, sizeof(*grbuf) * len);
375 	memcpy(grbuf, cred->cr_groups, sizeof(*grbuf) * len);
376 
377 	return (0);
378 }
379 
380 /*
381  * Match uids in two credentials.
382  */
383 int
384 kauth_cred_uidmatch(kauth_cred_t cred1, kauth_cred_t cred2)
385 {
386 	KASSERT(cred1 != NULL);
387 	KASSERT(cred2 != NULL);
388 
389 	if (cred1->cr_uid == cred2->cr_uid ||
390 	    cred1->cr_euid == cred2->cr_uid ||
391 	    cred1->cr_uid == cred2->cr_euid ||
392 	    cred1->cr_euid == cred2->cr_euid)
393 		return (1);
394 
395 	return (0);
396 }
397 
398 u_int
399 kauth_cred_getrefcnt(kauth_cred_t cred)
400 {
401 	KASSERT(cred != NULL);
402 
403 	return (cred->cr_refcnt);
404 }
405 
406 /*
407  * Convert userland credentials (struct uucred) to kauth_cred_t.
408  * XXX: For NFS & puffs
409  */
410 void
411 kauth_uucred_to_cred(kauth_cred_t cred, const struct uucred *uuc)
412 {
413 	KASSERT(cred != NULL);
414 	KASSERT(uuc != NULL);
415 
416 	cred->cr_refcnt = 1;
417 	cred->cr_uid = uuc->cr_uid;
418 	cred->cr_euid = uuc->cr_uid;
419 	cred->cr_svuid = uuc->cr_uid;
420 	cred->cr_gid = uuc->cr_gid;
421 	cred->cr_egid = uuc->cr_gid;
422 	cred->cr_svgid = uuc->cr_gid;
423 	cred->cr_ngroups = min(uuc->cr_ngroups, NGROUPS);
424 	kauth_cred_setgroups(cred, __UNCONST(uuc->cr_groups),
425 	    cred->cr_ngroups, -1);
426 }
427 
428 /*
429  * Convert kauth_cred_t to userland credentials (struct uucred).
430  * XXX: For NFS & puffs
431  */
432 void
433 kauth_cred_to_uucred(struct uucred *uuc, const kauth_cred_t cred)
434 {
435 	KASSERT(cred != NULL);
436 	KASSERT(uuc != NULL);
437 	int ng;
438 
439 	ng = min(cred->cr_ngroups, NGROUPS);
440 	uuc->cr_uid = cred->cr_euid;
441 	uuc->cr_gid = cred->cr_egid;
442 	uuc->cr_ngroups = ng;
443 	kauth_cred_getgroups(cred, uuc->cr_groups, ng);
444 }
445 
446 /*
447  * Compare kauth_cred_t and uucred credentials.
448  * XXX: Modelled after crcmp() for NFS.
449  */
450 int
451 kauth_cred_uucmp(kauth_cred_t cred, const struct uucred *uuc)
452 {
453 	KASSERT(cred != NULL);
454 	KASSERT(uuc != NULL);
455 
456 	if (cred->cr_euid == uuc->cr_uid &&
457 	    cred->cr_egid == uuc->cr_gid &&
458 	    cred->cr_ngroups == uuc->cr_ngroups) {
459 		int i;
460 
461 		/* Check if all groups from uuc appear in cred. */
462 		for (i = 0; i < uuc->cr_ngroups; i++) {
463 			int ismember;
464 
465 			ismember = 0;
466 			if (kauth_cred_ismember_gid(cred, uuc->cr_groups[i],
467 			    &ismember) != 0 || !ismember)
468 				return (1);
469 		}
470 
471 		return (0);
472 	}
473 
474 	return (1);
475 }
476 
477 /*
478  * Make a struct ucred out of a kauth_cred_t.  For compatibility.
479  */
480 void
481 kauth_cred_toucred(kauth_cred_t cred, struct ucred *uc)
482 {
483 	KASSERT(cred != NULL);
484 	KASSERT(uc != NULL);
485 
486 	uc->cr_ref = cred->cr_refcnt;
487 	uc->cr_uid = cred->cr_euid;
488 	uc->cr_gid = cred->cr_egid;
489 	uc->cr_ngroups = min(cred->cr_ngroups,
490 			     sizeof(uc->cr_groups) / sizeof(uc->cr_groups[0]));
491 	memcpy(uc->cr_groups, cred->cr_groups,
492 	       uc->cr_ngroups * sizeof(uc->cr_groups[0]));
493 }
494 
495 /*
496  * Make a struct pcred out of a kauth_cred_t.  For compatibility.
497  */
498 void
499 kauth_cred_topcred(kauth_cred_t cred, struct pcred *pc)
500 {
501 	KASSERT(cred != NULL);
502 	KASSERT(pc != NULL);
503 
504 	pc->pc_ucred = NULL;
505 	pc->p_ruid = cred->cr_uid;
506 	pc->p_svuid = cred->cr_svuid;
507 	pc->p_rgid = cred->cr_gid;
508 	pc->p_svgid = cred->cr_svgid;
509 	pc->p_refcnt = cred->cr_refcnt;
510 }
511 
512 /*
513  * Return kauth_cred_t for the current LWP.
514  */
515 kauth_cred_t
516 kauth_cred_get(void)
517 {
518 	return (curlwp->l_cred);
519 }
520 
521 /*
522  * Returns a scope matching the provided id.
523  * Requires the scope list lock to be held by the caller.
524  */
525 static kauth_scope_t
526 kauth_ifindscope(const char *id)
527 {
528 	kauth_scope_t scope;
529 
530 	/* XXX: assert lock on scope list? */
531 
532 	scope = NULL;
533 	SIMPLEQ_FOREACH(scope, &scope_list, next_scope) {
534 		if (strcmp(scope->id, id) == 0)
535 			break;
536 	}
537 
538 	return (scope);
539 }
540 
541 /*
542  * Register a new scope.
543  *
544  * id - identifier for the scope
545  * callback - the scope's default listener
546  * cookie - cookie to be passed to the listener(s)
547  */
548 kauth_scope_t
549 kauth_register_scope(const char *id, kauth_scope_callback_t callback,
550     void *cookie)
551 {
552 	kauth_scope_t scope;
553 	kauth_listener_t listener = NULL; /* XXX gcc */
554 
555 	/* Sanitize input */
556 	if (id == NULL)
557 		return (NULL);
558 
559 	/* Allocate space for a new scope and listener. */
560 	scope = pool_get(&kauth_scope_pool, PR_WAITOK);
561 	if (callback != NULL) {
562 		listener = pool_get(&kauth_listener_pool, PR_WAITOK);
563 	}
564 
565 	/* Acquire scope list lock. */
566 	simple_lock(&scopes_lock);
567 
568 	/* Check we don't already have a scope with the same id */
569 	if (kauth_ifindscope(id) != NULL) {
570 		simple_unlock(&scopes_lock);
571 
572 		pool_put(&kauth_scope_pool, scope);
573 		if (callback != NULL) {
574 			pool_put(&kauth_listener_pool, listener);
575 		}
576 
577 		return (NULL);
578 	}
579 
580 	/* Initialize new scope with parameters */
581 	scope->id = id;
582 	scope->cookie = cookie;
583 	scope->nlisteners = 1;
584 
585 	SIMPLEQ_INIT(&scope->listenq);
586 
587 	/* Add default listener */
588 	if (callback != NULL) {
589 		listener->func = callback;
590 		listener->scope = scope;
591 		listener->refcnt = 0;
592 		SIMPLEQ_INSERT_HEAD(&scope->listenq, listener, listener_next);
593 	}
594 
595 	/* Insert scope to scopes list */
596 	SIMPLEQ_INSERT_TAIL(&scope_list, scope, next_scope);
597 
598 	simple_unlock(&scopes_lock);
599 
600 	return (scope);
601 }
602 
603 /*
604  * Initialize the kernel authorization subsystem.
605  *
606  * Initialize the scopes list lock.
607  * Register built-in scopes: generic, process.
608  */
609 void
610 kauth_init(void)
611 {
612 	SIMPLEQ_INIT(&scope_list);
613 	simple_lock_init(&scopes_lock);
614 
615 	/* Register generic scope. */
616 	kauth_builtin_scope_generic = kauth_register_scope(KAUTH_SCOPE_GENERIC,
617 	    NULL, NULL);
618 
619 	/* Register system scope. */
620 	kauth_builtin_scope_system = kauth_register_scope(KAUTH_SCOPE_SYSTEM,
621 	    NULL, NULL);
622 
623 	/* Register process scope. */
624 	kauth_builtin_scope_process = kauth_register_scope(KAUTH_SCOPE_PROCESS,
625 	    NULL, NULL);
626 
627 	/* Register network scope. */
628 	kauth_builtin_scope_network = kauth_register_scope(KAUTH_SCOPE_NETWORK,
629 	    NULL, NULL);
630 
631 	/* Register machdep scope. */
632 	kauth_builtin_scope_machdep = kauth_register_scope(KAUTH_SCOPE_MACHDEP,
633 	    NULL, NULL);
634 
635 	/* Register device scope. */
636 	kauth_builtin_scope_device = kauth_register_scope(KAUTH_SCOPE_DEVICE,
637 	    NULL, NULL);
638 }
639 
640 /*
641  * Deregister a scope.
642  * Requires scope list lock to be held by the caller.
643  *
644  * scope - the scope to deregister
645  */
646 void
647 kauth_deregister_scope(kauth_scope_t scope)
648 {
649 	if (scope != NULL) {
650 		/* Remove scope from list */
651 		SIMPLEQ_REMOVE(&scope_list, scope, kauth_scope, next_scope);
652 	}
653 }
654 
655 /*
656  * Register a listener.
657  *
658  * id - scope identifier.
659  * callback - the callback routine for the listener.
660  * cookie - cookie to pass unmoidfied to the callback.
661  */
662 kauth_listener_t
663 kauth_listen_scope(const char *id, kauth_scope_callback_t callback,
664    void *cookie)
665 {
666 	kauth_scope_t scope;
667 	kauth_listener_t listener;
668 
669 	/* Find scope struct */
670 	simple_lock(&scopes_lock);
671 	scope = kauth_ifindscope(id);
672 	simple_unlock(&scopes_lock);
673 	if (scope == NULL)
674 		return (NULL);
675 
676 	/* Allocate listener */
677 	listener = pool_get(&kauth_listener_pool, PR_WAITOK);
678 
679 	/* Initialize listener with parameters */
680 	listener->func = callback;
681 	listener->refcnt = 0;
682 
683 	/* Add listener to scope */
684 	SIMPLEQ_INSERT_TAIL(&scope->listenq, listener, listener_next);
685 
686 	/* Raise number of listeners on scope. */
687 	scope->nlisteners++;
688 	listener->scope = scope;
689 
690 	listeners_have_been_loaded = TRUE;
691 
692 	return (listener);
693 }
694 
695 /*
696  * Deregister a listener.
697  *
698  * listener - listener reference as returned from kauth_listen_scope().
699  */
700 void
701 kauth_unlisten_scope(kauth_listener_t listener)
702 {
703 	if (listener != NULL) {
704 		SIMPLEQ_REMOVE(&listener->scope->listenq, listener,
705 		    kauth_listener, listener_next);
706 		listener->scope->nlisteners--;
707 	}
708 }
709 
710 /*
711  * Authorize a request.
712  *
713  * scope - the scope of the request as defined by KAUTH_SCOPE_* or as
714  *	   returned from kauth_register_scope().
715  * credential - credentials of the user ("actor") making the request.
716  * action - request identifier.
717  * arg[0-3] - passed unmodified to listener(s).
718  */
719 int
720 kauth_authorize_action(kauth_scope_t scope, kauth_cred_t cred,
721 		       kauth_action_t action, void *arg0, void *arg1,
722 		       void *arg2, void *arg3)
723 {
724 	kauth_listener_t listener;
725 	int error, allow, fail;
726 
727 #if 0 /* defined(LOCKDEBUG) */
728 	spinlock_switchcheck();
729 	simple_lock_only_held(NULL, "kauth_authorize_action");
730 #endif
731 
732 	KASSERT(cred != NULL);
733 	KASSERT(action != 0);
734 
735 	/* Short-circuit requests coming from the kernel. */
736 	if (cred == NOCRED || cred == FSCRED)
737 		return (0);
738 
739 	KASSERT(scope != NULL);
740 
741 	if (!listeners_have_been_loaded) {
742 		KASSERT(SIMPLEQ_EMPTY(&scope->listenq));
743 
744 		return (0);
745 	}
746 
747 	fail = 0;
748 	allow = 0;
749 	SIMPLEQ_FOREACH(listener, &scope->listenq, listener_next) {
750 		error = listener->func(cred, action, scope->cookie, arg0,
751 				       arg1, arg2, arg3);
752 
753 		if (error == KAUTH_RESULT_ALLOW)
754 			allow = 1;
755 		else if (error == KAUTH_RESULT_DENY)
756 			fail = 1;
757 	}
758 
759 	return ((allow && !fail) ? 0 : EPERM);
760 };
761 
762 /*
763  * Generic scope authorization wrapper.
764  */
765 int
766 kauth_authorize_generic(kauth_cred_t cred, kauth_action_t action, void *arg0)
767 {
768 	return (kauth_authorize_action(kauth_builtin_scope_generic, cred,
769 	    action, arg0, NULL, NULL, NULL));
770 }
771 
772 /*
773  * System scope authorization wrapper.
774  */
775 int
776 kauth_authorize_system(kauth_cred_t cred, kauth_action_t action,
777     enum kauth_system_req req, void *arg1, void *arg2, void *arg3)
778 {
779 	return (kauth_authorize_action(kauth_builtin_scope_system, cred,
780 	    action, (void *)req, arg1, arg2, arg3));
781 }
782 
783 /*
784  * Process scope authorization wrapper.
785  */
786 int
787 kauth_authorize_process(kauth_cred_t cred, kauth_action_t action,
788     struct proc *p, void *arg1, void *arg2, void *arg3)
789 {
790 	return (kauth_authorize_action(kauth_builtin_scope_process, cred,
791 	    action, p, arg1, arg2, arg3));
792 }
793 
794 /*
795  * Network scope authorization wrapper.
796  */
797 int
798 kauth_authorize_network(kauth_cred_t cred, kauth_action_t action,
799     enum kauth_network_req req, void *arg1, void *arg2, void *arg3)
800 {
801 	return (kauth_authorize_action(kauth_builtin_scope_network, cred,
802 	    action, (void *)req, arg1, arg2, arg3));
803 }
804 
805 int
806 kauth_authorize_machdep(kauth_cred_t cred, kauth_action_t action,
807     enum kauth_machdep_req req, void *arg1, void *arg2, void *arg3)
808 {
809 	return (kauth_authorize_action(kauth_builtin_scope_machdep, cred,
810 	    action, (void *)req, arg1, arg2, arg3));
811 }
812 
813 int
814 kauth_authorize_device(kauth_cred_t cred, kauth_action_t action,
815     void *arg0, void *arg1, void *arg2, void *arg3)
816 {
817 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
818 	    action, arg0, arg1, arg2, arg3));
819 }
820 
821 int
822 kauth_authorize_device_tty(kauth_cred_t cred, kauth_action_t action,
823     struct tty *tty)
824 {
825 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
826 	    action, tty, NULL, NULL, NULL));
827 }
828 
829 int
830 kauth_authorize_device_spec(kauth_cred_t cred, enum kauth_device_req req,
831     struct vnode *vp)
832 {
833 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
834 	    KAUTH_DEVICE_RAWIO_SPEC, (void *)req, vp, NULL, NULL));
835 }
836 
837 int
838 kauth_authorize_device_passthru(kauth_cred_t cred, dev_t dev, void *data)
839 {
840 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
841 	    KAUTH_DEVICE_RAWIO_PASSTHRU, 0, (void *)(u_long)dev, data,
842 	    NULL));
843 }
844