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kern_auth.c revision 1.18.2.7
      1 /* $NetBSD: kern_auth.c,v 1.18.2.7 2007/02/09 21:03:53 ad Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2005, 2006 Elad Efrat <elad (at) 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. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: kern_auth.c,v 1.18.2.7 2007/02/09 21:03:53 ad Exp $");
     32 
     33 #define	_KAUTH_PRIVATE
     34 
     35 #include <sys/param.h>
     36 #include <sys/queue.h>
     37 #include <sys/proc.h>
     38 #include <sys/ucred.h>
     39 #include <sys/pool.h>
     40 #include <sys/kauth.h>
     41 #include <sys/kauth_impl.h>
     42 #include <sys/kmem.h>
     43 #include <sys/rwlock.h>
     44 
     45 /*
     46  * Secmodel-specific credentials.
     47  */
     48 struct kauth_key {
     49 	const char *ks_secmodel;	/* secmodel */
     50 	specificdata_key_t ks_key;	/* key */
     51 };
     52 
     53 /*
     54  * Listener.
     55  */
     56 struct kauth_listener {
     57 	kauth_scope_callback_t		func;		/* callback */
     58 	kauth_scope_t			scope;		/* scope backpointer */
     59 	u_int				refcnt;		/* reference count */
     60 	SIMPLEQ_ENTRY(kauth_listener)	listener_next;	/* listener list */
     61 };
     62 
     63 /*
     64  * Scope.
     65  */
     66 struct kauth_scope {
     67 	const char		       *id;		/* scope name */
     68 	void			       *cookie;		/* user cookie */
     69 	u_int				nlisteners;	/* # of listeners */
     70 	SIMPLEQ_HEAD(, kauth_listener)	listenq;	/* listener list */
     71 	SIMPLEQ_ENTRY(kauth_scope)	next_scope;	/* scope list */
     72 };
     73 
     74 static int kauth_cred_hook(kauth_cred_t, kauth_action_t, void *, void *);
     75 
     76 static POOL_INIT(kauth_cred_pool, sizeof(struct kauth_cred), 0, 0, 0,
     77     "kauthcredpl", &pool_allocator_nointr);
     78 
     79 /* List of scopes and its lock. */
     80 static SIMPLEQ_HEAD(, kauth_scope) scope_list;
     81 
     82 /* Built-in scopes: generic, process. */
     83 static kauth_scope_t kauth_builtin_scope_generic;
     84 static kauth_scope_t kauth_builtin_scope_system;
     85 static kauth_scope_t kauth_builtin_scope_process;
     86 static kauth_scope_t kauth_builtin_scope_network;
     87 static kauth_scope_t kauth_builtin_scope_machdep;
     88 static kauth_scope_t kauth_builtin_scope_device;
     89 static kauth_scope_t kauth_builtin_scope_cred;
     90 
     91 static unsigned int nsecmodels = 0;
     92 
     93 static specificdata_domain_t kauth_domain;
     94 krwlock_t	kauth_lock;
     95 
     96 /* Allocate new, empty kauth credentials. */
     97 kauth_cred_t
     98 kauth_cred_alloc(void)
     99 {
    100 	kauth_cred_t cred;
    101 
    102 	cred = pool_get(&kauth_cred_pool, PR_WAITOK);
    103 	memset(cred, 0, sizeof(*cred));
    104 	mutex_init(&cred->cr_lock, MUTEX_DEFAULT, IPL_NONE);
    105 	cred->cr_refcnt = 1;
    106 	specificdata_init(kauth_domain, &cred->cr_sd);
    107 	kauth_cred_hook(cred, KAUTH_CRED_INIT, NULL, NULL);
    108 
    109 	return (cred);
    110 }
    111 
    112 /* Increment reference count to cred. */
    113 void
    114 kauth_cred_hold(kauth_cred_t cred)
    115 {
    116 	KASSERT(cred != NULL);
    117 	KASSERT(cred->cr_refcnt > 0);
    118 
    119         mutex_enter(&cred->cr_lock);
    120         cred->cr_refcnt++;
    121         mutex_exit(&cred->cr_lock);
    122 }
    123 
    124 /* Decrease reference count to cred. If reached zero, free it. */
    125 void
    126 kauth_cred_free(kauth_cred_t cred)
    127 {
    128 	u_int refcnt;
    129 
    130 	KASSERT(cred != NULL);
    131 	KASSERT(cred->cr_refcnt > 0);
    132 
    133 	mutex_enter(&cred->cr_lock);
    134 	refcnt = --cred->cr_refcnt;
    135 	mutex_exit(&cred->cr_lock);
    136 
    137 	if (refcnt == 0) {
    138 		kauth_cred_hook(cred, KAUTH_CRED_FREE, NULL, NULL);
    139 		specificdata_fini(kauth_domain, &cred->cr_sd);
    140 		mutex_destroy(&cred->cr_lock);
    141 		pool_put(&kauth_cred_pool, cred);
    142 	}
    143 }
    144 
    145 void
    146 kauth_cred_clone(kauth_cred_t from, kauth_cred_t to)
    147 {
    148 	KASSERT(from != NULL);
    149 	KASSERT(to != NULL);
    150 	KASSERT(from->cr_refcnt > 0);
    151 
    152 	to->cr_uid = from->cr_uid;
    153 	to->cr_euid = from->cr_euid;
    154 	to->cr_svuid = from->cr_svuid;
    155 	to->cr_gid = from->cr_gid;
    156 	to->cr_egid = from->cr_egid;
    157 	to->cr_svgid = from->cr_svgid;
    158 	to->cr_ngroups = from->cr_ngroups;
    159 	memcpy(to->cr_groups, from->cr_groups, sizeof(to->cr_groups));
    160 
    161 	kauth_cred_hook(from, KAUTH_CRED_COPY, to, NULL);
    162 }
    163 
    164 /*
    165  * Duplicate cred and return a new kauth_cred_t.
    166  */
    167 kauth_cred_t
    168 kauth_cred_dup(kauth_cred_t cred)
    169 {
    170 	kauth_cred_t new_cred;
    171 
    172 	KASSERT(cred != NULL);
    173 	KASSERT(cred->cr_refcnt > 0);
    174 
    175 	new_cred = kauth_cred_alloc();
    176 
    177 	kauth_cred_clone(cred, new_cred);
    178 
    179 	return (new_cred);
    180 }
    181 
    182 /*
    183  * Similar to crcopy(), only on a kauth_cred_t.
    184  * XXX: Is this even needed? [kauth_cred_copy]
    185  */
    186 kauth_cred_t
    187 kauth_cred_copy(kauth_cred_t cred)
    188 {
    189 	kauth_cred_t new_cred;
    190 
    191 	KASSERT(cred != NULL);
    192 	KASSERT(cred->cr_refcnt > 0);
    193 
    194 	/* If the provided credentials already have one reference, use them. */
    195 	if (cred->cr_refcnt == 1)
    196 		return (cred);
    197 
    198 	new_cred = kauth_cred_alloc();
    199 
    200 	kauth_cred_clone(cred, new_cred);
    201 
    202 	kauth_cred_free(cred);
    203 
    204 	return (new_cred);
    205 }
    206 
    207 void
    208 kauth_proc_fork(struct proc *parent, struct proc *child)
    209 {
    210 
    211 	mutex_enter(&parent->p_mutex);
    212 	kauth_cred_hold(parent->p_cred);
    213 	child->p_cred = parent->p_cred;
    214 	mutex_exit(&parent->p_mutex);
    215 
    216 	/* XXX: relies on parent process stalling during fork() */
    217 	kauth_cred_hook(parent->p_cred, KAUTH_CRED_FORK, parent,
    218 	    child);
    219 }
    220 
    221 uid_t
    222 kauth_cred_getuid(kauth_cred_t cred)
    223 {
    224 	KASSERT(cred != NULL);
    225 
    226 	return (cred->cr_uid);
    227 }
    228 
    229 uid_t
    230 kauth_cred_geteuid(kauth_cred_t cred)
    231 {
    232 	KASSERT(cred != NULL);
    233 
    234 	return (cred->cr_euid);
    235 }
    236 
    237 uid_t
    238 kauth_cred_getsvuid(kauth_cred_t cred)
    239 {
    240 	KASSERT(cred != NULL);
    241 
    242 	return (cred->cr_svuid);
    243 }
    244 
    245 gid_t
    246 kauth_cred_getgid(kauth_cred_t cred)
    247 {
    248 	KASSERT(cred != NULL);
    249 
    250 	return (cred->cr_gid);
    251 }
    252 
    253 gid_t
    254 kauth_cred_getegid(kauth_cred_t cred)
    255 {
    256 	KASSERT(cred != NULL);
    257 
    258 	return (cred->cr_egid);
    259 }
    260 
    261 gid_t
    262 kauth_cred_getsvgid(kauth_cred_t cred)
    263 {
    264 	KASSERT(cred != NULL);
    265 
    266 	return (cred->cr_svgid);
    267 }
    268 
    269 void
    270 kauth_cred_setuid(kauth_cred_t cred, uid_t uid)
    271 {
    272 	KASSERT(cred != NULL);
    273 	KASSERT(cred->cr_refcnt == 1);
    274 
    275 	cred->cr_uid = uid;
    276 }
    277 
    278 void
    279 kauth_cred_seteuid(kauth_cred_t cred, uid_t uid)
    280 {
    281 	KASSERT(cred != NULL);
    282 	KASSERT(cred->cr_refcnt == 1);
    283 
    284 	cred->cr_euid = uid;
    285 }
    286 
    287 void
    288 kauth_cred_setsvuid(kauth_cred_t cred, uid_t uid)
    289 {
    290 	KASSERT(cred != NULL);
    291 	KASSERT(cred->cr_refcnt == 1);
    292 
    293 	cred->cr_svuid = uid;
    294 }
    295 
    296 void
    297 kauth_cred_setgid(kauth_cred_t cred, gid_t gid)
    298 {
    299 	KASSERT(cred != NULL);
    300 	KASSERT(cred->cr_refcnt == 1);
    301 
    302 	cred->cr_gid = gid;
    303 }
    304 
    305 void
    306 kauth_cred_setegid(kauth_cred_t cred, gid_t gid)
    307 {
    308 	KASSERT(cred != NULL);
    309 	KASSERT(cred->cr_refcnt == 1);
    310 
    311 	cred->cr_egid = gid;
    312 }
    313 
    314 void
    315 kauth_cred_setsvgid(kauth_cred_t cred, gid_t gid)
    316 {
    317 	KASSERT(cred != NULL);
    318 	KASSERT(cred->cr_refcnt == 1);
    319 
    320 	cred->cr_svgid = gid;
    321 }
    322 
    323 /* Checks if gid is a member of the groups in cred. */
    324 int
    325 kauth_cred_ismember_gid(kauth_cred_t cred, gid_t gid, int *resultp)
    326 {
    327 	int i;
    328 
    329 	KASSERT(cred != NULL);
    330 	KASSERT(resultp != NULL);
    331 
    332 	*resultp = 0;
    333 
    334 	for (i = 0; i < cred->cr_ngroups; i++)
    335 		if (cred->cr_groups[i] == gid) {
    336 			*resultp = 1;
    337 			break;
    338 		}
    339 
    340 	return (0);
    341 }
    342 
    343 u_int
    344 kauth_cred_ngroups(kauth_cred_t cred)
    345 {
    346 	KASSERT(cred != NULL);
    347 
    348 	return (cred->cr_ngroups);
    349 }
    350 
    351 /*
    352  * Return the group at index idx from the groups in cred.
    353  */
    354 gid_t
    355 kauth_cred_group(kauth_cred_t cred, u_int idx)
    356 {
    357 	KASSERT(cred != NULL);
    358 	KASSERT(idx < cred->cr_ngroups);
    359 
    360 	return (cred->cr_groups[idx]);
    361 }
    362 
    363 /* XXX elad: gmuid is unused for now. */
    364 int
    365 kauth_cred_setgroups(kauth_cred_t cred, gid_t *grbuf, size_t len, uid_t gmuid)
    366 {
    367 	KASSERT(cred != NULL);
    368 	KASSERT(cred->cr_refcnt == 1);
    369 	KASSERT(len <= sizeof(cred->cr_groups) / sizeof(cred->cr_groups[0]));
    370 
    371 	if (len)
    372 		memcpy(cred->cr_groups, grbuf, len * sizeof(cred->cr_groups[0]));
    373 	memset(cred->cr_groups + len, 0xff,
    374 	    sizeof(cred->cr_groups) - (len * sizeof(cred->cr_groups[0])));
    375 
    376 	cred->cr_ngroups = len;
    377 
    378 	return (0);
    379 }
    380 
    381 int
    382 kauth_cred_getgroups(kauth_cred_t cred, gid_t *grbuf, size_t len)
    383 {
    384 	KASSERT(cred != NULL);
    385 	KASSERT(len <= cred->cr_ngroups);
    386 
    387 	memset(grbuf, 0xff, sizeof(*grbuf) * len);
    388 	memcpy(grbuf, cred->cr_groups, sizeof(*grbuf) * len);
    389 
    390 	return (0);
    391 }
    392 
    393 int
    394 kauth_register_key(const char *secmodel, kauth_key_t *result)
    395 {
    396 	kauth_key_t k;
    397 	specificdata_key_t key;
    398 	int error;
    399 
    400 	KASSERT(result != NULL);
    401 
    402 	error = specificdata_key_create(kauth_domain, &key, NULL);
    403 	if (error)
    404 		return (error);
    405 
    406 	k = kmem_alloc(sizeof(*k), KM_SLEEP);
    407 	k->ks_secmodel = secmodel;
    408 	k->ks_key = key;
    409 
    410 	*result = k;
    411 
    412 	return (0);
    413 }
    414 
    415 int
    416 kauth_deregister_key(kauth_key_t key)
    417 {
    418 	KASSERT(key != NULL);
    419 
    420 	specificdata_key_delete(kauth_domain, key->ks_key);
    421 	kmem_free(key, sizeof(*key));
    422 
    423 	return (0);
    424 }
    425 
    426 void *
    427 kauth_cred_getdata(kauth_cred_t cred, kauth_key_t key)
    428 {
    429 	KASSERT(cred != NULL);
    430 	KASSERT(key != NULL);
    431 
    432 	return (specificdata_getspecific(kauth_domain, &cred->cr_sd,
    433 	    key->ks_key));
    434 }
    435 
    436 void
    437 kauth_cred_setdata(kauth_cred_t cred, kauth_key_t key, void *data)
    438 {
    439 	KASSERT(cred != NULL);
    440 	KASSERT(key != NULL);
    441 
    442 	specificdata_setspecific(kauth_domain, &cred->cr_sd, key->ks_key, data);
    443 }
    444 
    445 /*
    446  * Match uids in two credentials.
    447  */
    448 int
    449 kauth_cred_uidmatch(kauth_cred_t cred1, kauth_cred_t cred2)
    450 {
    451 	KASSERT(cred1 != NULL);
    452 	KASSERT(cred2 != NULL);
    453 
    454 	if (cred1->cr_uid == cred2->cr_uid ||
    455 	    cred1->cr_euid == cred2->cr_uid ||
    456 	    cred1->cr_uid == cred2->cr_euid ||
    457 	    cred1->cr_euid == cred2->cr_euid)
    458 		return (1);
    459 
    460 	return (0);
    461 }
    462 
    463 u_int
    464 kauth_cred_getrefcnt(kauth_cred_t cred)
    465 {
    466 	KASSERT(cred != NULL);
    467 
    468 	return (cred->cr_refcnt);
    469 }
    470 
    471 /*
    472  * Convert userland credentials (struct uucred) to kauth_cred_t.
    473  * XXX: For NFS & puffs
    474  */
    475 void
    476 kauth_uucred_to_cred(kauth_cred_t cred, const struct uucred *uuc)
    477 {
    478 	KASSERT(cred != NULL);
    479 	KASSERT(uuc != NULL);
    480 
    481 	cred->cr_refcnt = 1;
    482 	cred->cr_uid = uuc->cr_uid;
    483 	cred->cr_euid = uuc->cr_uid;
    484 	cred->cr_svuid = uuc->cr_uid;
    485 	cred->cr_gid = uuc->cr_gid;
    486 	cred->cr_egid = uuc->cr_gid;
    487 	cred->cr_svgid = uuc->cr_gid;
    488 	cred->cr_ngroups = min(uuc->cr_ngroups, NGROUPS);
    489 	kauth_cred_setgroups(cred, __UNCONST(uuc->cr_groups),
    490 	    cred->cr_ngroups, -1);
    491 }
    492 
    493 /*
    494  * Convert kauth_cred_t to userland credentials (struct uucred).
    495  * XXX: For NFS & puffs
    496  */
    497 void
    498 kauth_cred_to_uucred(struct uucred *uuc, const kauth_cred_t cred)
    499 {
    500 	KASSERT(cred != NULL);
    501 	KASSERT(uuc != NULL);
    502 	int ng;
    503 
    504 	ng = min(cred->cr_ngroups, NGROUPS);
    505 	uuc->cr_uid = cred->cr_euid;
    506 	uuc->cr_gid = cred->cr_egid;
    507 	uuc->cr_ngroups = ng;
    508 	kauth_cred_getgroups(cred, uuc->cr_groups, ng);
    509 }
    510 
    511 /*
    512  * Compare kauth_cred_t and uucred credentials.
    513  * XXX: Modelled after crcmp() for NFS.
    514  */
    515 int
    516 kauth_cred_uucmp(kauth_cred_t cred, const struct uucred *uuc)
    517 {
    518 	KASSERT(cred != NULL);
    519 	KASSERT(uuc != NULL);
    520 
    521 	if (cred->cr_euid == uuc->cr_uid &&
    522 	    cred->cr_egid == uuc->cr_gid &&
    523 	    cred->cr_ngroups == uuc->cr_ngroups) {
    524 		int i;
    525 
    526 		/* Check if all groups from uuc appear in cred. */
    527 		for (i = 0; i < uuc->cr_ngroups; i++) {
    528 			int ismember;
    529 
    530 			ismember = 0;
    531 			if (kauth_cred_ismember_gid(cred, uuc->cr_groups[i],
    532 			    &ismember) != 0 || !ismember)
    533 				return (1);
    534 		}
    535 
    536 		return (0);
    537 	}
    538 
    539 	return (1);
    540 }
    541 
    542 /*
    543  * Make a struct ucred out of a kauth_cred_t.  For compatibility.
    544  */
    545 void
    546 kauth_cred_toucred(kauth_cred_t cred, struct ucred *uc)
    547 {
    548 	KASSERT(cred != NULL);
    549 	KASSERT(uc != NULL);
    550 
    551 	uc->cr_ref = cred->cr_refcnt;
    552 	uc->cr_uid = cred->cr_euid;
    553 	uc->cr_gid = cred->cr_egid;
    554 	uc->cr_ngroups = min(cred->cr_ngroups,
    555 			     sizeof(uc->cr_groups) / sizeof(uc->cr_groups[0]));
    556 	memcpy(uc->cr_groups, cred->cr_groups,
    557 	       uc->cr_ngroups * sizeof(uc->cr_groups[0]));
    558 }
    559 
    560 /*
    561  * Make a struct pcred out of a kauth_cred_t.  For compatibility.
    562  */
    563 void
    564 kauth_cred_topcred(kauth_cred_t cred, struct pcred *pc)
    565 {
    566 	KASSERT(cred != NULL);
    567 	KASSERT(pc != NULL);
    568 
    569 	pc->pc_ucred = NULL;
    570 	pc->p_ruid = cred->cr_uid;
    571 	pc->p_svuid = cred->cr_svuid;
    572 	pc->p_rgid = cred->cr_gid;
    573 	pc->p_svgid = cred->cr_svgid;
    574 	pc->p_refcnt = cred->cr_refcnt;
    575 }
    576 
    577 /*
    578  * Return kauth_cred_t for the current LWP.
    579  */
    580 kauth_cred_t
    581 kauth_cred_get(void)
    582 {
    583 	return (curlwp->l_cred);
    584 }
    585 
    586 /*
    587  * Returns a scope matching the provided id.
    588  * Requires the scope list lock to be held by the caller.
    589  */
    590 static kauth_scope_t
    591 kauth_ifindscope(const char *id)
    592 {
    593 	kauth_scope_t scope;
    594 
    595 	KASSERT(rw_lock_held(&kauth_lock));
    596 
    597 	scope = NULL;
    598 	SIMPLEQ_FOREACH(scope, &scope_list, next_scope) {
    599 		if (strcmp(scope->id, id) == 0)
    600 			break;
    601 	}
    602 
    603 	return (scope);
    604 }
    605 
    606 /*
    607  * Register a new scope.
    608  *
    609  * id - identifier for the scope
    610  * callback - the scope's default listener
    611  * cookie - cookie to be passed to the listener(s)
    612  */
    613 kauth_scope_t
    614 kauth_register_scope(const char *id, kauth_scope_callback_t callback,
    615     void *cookie)
    616 {
    617 	kauth_scope_t scope;
    618 	kauth_listener_t listener = NULL; /* XXX gcc */
    619 
    620 	/* Sanitize input */
    621 	if (id == NULL)
    622 		return (NULL);
    623 
    624 	/* Allocate space for a new scope and listener. */
    625 	scope = kmem_alloc(sizeof(*scope), KM_SLEEP);
    626 	if (scope == NULL)
    627 		return NULL;
    628 	if (callback != NULL) {
    629 		listener = kmem_alloc(sizeof(*listener), KM_SLEEP);
    630 		if (listener == NULL) {
    631 			kmem_free(scope, sizeof(*scope));
    632 			return (NULL);
    633 		}
    634 	}
    635 
    636 	/*
    637 	 * Acquire scope list lock.
    638 	 */
    639 	rw_enter(&kauth_lock, RW_WRITER);
    640 
    641 	/* Check we don't already have a scope with the same id */
    642 	if (kauth_ifindscope(id) != NULL) {
    643 		rw_exit(&kauth_lock);
    644 
    645 		kmem_free(scope, sizeof(*scope));
    646 		if (callback != NULL)
    647 			kmem_free(listener, sizeof(*listener));
    648 
    649 		return (NULL);
    650 	}
    651 
    652 	/* Initialize new scope with parameters */
    653 	scope->id = id;
    654 	scope->cookie = cookie;
    655 	scope->nlisteners = 1;
    656 
    657 	SIMPLEQ_INIT(&scope->listenq);
    658 
    659 	/* Add default listener */
    660 	if (callback != NULL) {
    661 		listener->func = callback;
    662 		listener->scope = scope;
    663 		listener->refcnt = 0;
    664 		SIMPLEQ_INSERT_HEAD(&scope->listenq, listener, listener_next);
    665 	}
    666 
    667 	/* Insert scope to scopes list */
    668 	SIMPLEQ_INSERT_TAIL(&scope_list, scope, next_scope);
    669 
    670 	rw_exit(&kauth_lock);
    671 
    672 	return (scope);
    673 }
    674 
    675 /*
    676  * Initialize the kernel authorization subsystem.
    677  *
    678  * Initialize the scopes list lock.
    679  * Create specificdata domain.
    680  * Register the credentials scope, used in kauth(9) internally.
    681  * Register built-in scopes: generic, system, process, network, machdep, device.
    682  */
    683 void
    684 kauth_init(void)
    685 {
    686 	SIMPLEQ_INIT(&scope_list);
    687 	rw_init(&kauth_lock);
    688 
    689 	/* Create specificdata domain. */
    690 	kauth_domain = specificdata_domain_create();
    691 
    692 	/* Register credentials scope. */
    693 	kauth_builtin_scope_cred =
    694 	    kauth_register_scope(KAUTH_SCOPE_CRED, NULL, NULL);
    695 
    696 	/* Register generic scope. */
    697 	kauth_builtin_scope_generic = kauth_register_scope(KAUTH_SCOPE_GENERIC,
    698 	    NULL, NULL);
    699 
    700 	/* Register system scope. */
    701 	kauth_builtin_scope_system = kauth_register_scope(KAUTH_SCOPE_SYSTEM,
    702 	    NULL, NULL);
    703 
    704 	/* Register process scope. */
    705 	kauth_builtin_scope_process = kauth_register_scope(KAUTH_SCOPE_PROCESS,
    706 	    NULL, NULL);
    707 
    708 	/* Register network scope. */
    709 	kauth_builtin_scope_network = kauth_register_scope(KAUTH_SCOPE_NETWORK,
    710 	    NULL, NULL);
    711 
    712 	/* Register machdep scope. */
    713 	kauth_builtin_scope_machdep = kauth_register_scope(KAUTH_SCOPE_MACHDEP,
    714 	    NULL, NULL);
    715 
    716 	/* Register device scope. */
    717 	kauth_builtin_scope_device = kauth_register_scope(KAUTH_SCOPE_DEVICE,
    718 	    NULL, NULL);
    719 }
    720 
    721 /*
    722  * Deregister a scope.
    723  * Requires scope list lock to be held by the caller.
    724  *
    725  * scope - the scope to deregister
    726  */
    727 void
    728 kauth_deregister_scope(kauth_scope_t scope)
    729 {
    730 	if (scope != NULL) {
    731 		/* Remove scope from list */
    732 		SIMPLEQ_REMOVE(&scope_list, scope, kauth_scope, next_scope);
    733 		kmem_free(scope, sizeof(*scope));
    734 	}
    735 }
    736 
    737 /*
    738  * Register a listener.
    739  *
    740  * id - scope identifier.
    741  * callback - the callback routine for the listener.
    742  * cookie - cookie to pass unmoidfied to the callback.
    743  */
    744 kauth_listener_t
    745 kauth_listen_scope(const char *id, kauth_scope_callback_t callback,
    746    void *cookie)
    747 {
    748 	kauth_scope_t scope;
    749 	kauth_listener_t listener;
    750 
    751 	listener = kmem_alloc(sizeof(*listener), KM_SLEEP);
    752 	if (listener == NULL)
    753 		return (NULL);
    754 
    755 	rw_enter(&kauth_lock, RW_WRITER);
    756 
    757 	/*
    758 	 * Find scope struct.
    759 	 */
    760 	scope = kauth_ifindscope(id);
    761 	if (scope == NULL) {
    762 		rw_exit(&kauth_lock);
    763 		kmem_free(listener, sizeof(*listener));
    764 		return (NULL);
    765 	}
    766 
    767 	/* Allocate listener */
    768 
    769 	/* Initialize listener with parameters */
    770 	listener->func = callback;
    771 	listener->refcnt = 0;
    772 
    773 	/* Add listener to scope */
    774 	SIMPLEQ_INSERT_TAIL(&scope->listenq, listener, listener_next);
    775 
    776 	/* Raise number of listeners on scope. */
    777 	scope->nlisteners++;
    778 	listener->scope = scope;
    779 
    780 	rw_exit(&kauth_lock);
    781 
    782 	return (listener);
    783 }
    784 
    785 /*
    786  * Deregister a listener.
    787  *
    788  * listener - listener reference as returned from kauth_listen_scope().
    789  */
    790 void
    791 kauth_unlisten_scope(kauth_listener_t listener)
    792 {
    793 
    794 	if (listener != NULL) {
    795 		rw_enter(&kauth_lock, RW_WRITER);
    796 		SIMPLEQ_REMOVE(&listener->scope->listenq, listener,
    797 		    kauth_listener, listener_next);
    798 		listener->scope->nlisteners--;
    799 		rw_exit(&kauth_lock);
    800 		kmem_free(listener, sizeof(*listener));
    801 	}
    802 }
    803 
    804 /*
    805  * Authorize a request.
    806  *
    807  * scope - the scope of the request as defined by KAUTH_SCOPE_* or as
    808  *	   returned from kauth_register_scope().
    809  * credential - credentials of the user ("actor") making the request.
    810  * action - request identifier.
    811  * arg[0-3] - passed unmodified to listener(s).
    812  */
    813 int
    814 kauth_authorize_action(kauth_scope_t scope, kauth_cred_t cred,
    815 		       kauth_action_t action, void *arg0, void *arg1,
    816 		       void *arg2, void *arg3)
    817 {
    818 	kauth_listener_t listener;
    819 	int error, allow, fail;
    820 
    821 #if 0 /* defined(LOCKDEBUG) */
    822 	spinlock_switchcheck();
    823 	simple_lock_only_held(NULL, "kauth_authorize_action");
    824 #endif
    825 
    826 	KASSERT(cred != NULL);
    827 	KASSERT(action != 0);
    828 
    829 	/* Short-circuit requests coming from the kernel. */
    830 	if (cred == NOCRED || cred == FSCRED)
    831 		return (0);
    832 
    833 	KASSERT(scope != NULL);
    834 
    835 	fail = 0;
    836 	allow = 0;
    837 
    838 	/* rw_enter(&kauth_lock, RW_READER); XXX not yet */
    839 	SIMPLEQ_FOREACH(listener, &scope->listenq, listener_next) {
    840 		error = listener->func(cred, action, scope->cookie, arg0,
    841 		    arg1, arg2, arg3);
    842 
    843 		if (error == KAUTH_RESULT_ALLOW)
    844 			allow = 1;
    845 		else if (error == KAUTH_RESULT_DENY)
    846 			fail = 1;
    847 	}
    848 	/* rw_exit(&kauth_lock); */
    849 
    850 	if (fail)
    851 		return (EPERM);
    852 
    853 	if (allow)
    854 		return (0);
    855 
    856 	if (!nsecmodels)
    857 		return (0);
    858 
    859 	return (EPERM);
    860 };
    861 
    862 /*
    863  * Generic scope authorization wrapper.
    864  */
    865 int
    866 kauth_authorize_generic(kauth_cred_t cred, kauth_action_t action, void *arg0)
    867 {
    868 	return (kauth_authorize_action(kauth_builtin_scope_generic, cred,
    869 	    action, arg0, NULL, NULL, NULL));
    870 }
    871 
    872 /*
    873  * System scope authorization wrapper.
    874  */
    875 int
    876 kauth_authorize_system(kauth_cred_t cred, kauth_action_t action,
    877     enum kauth_system_req req, void *arg1, void *arg2, void *arg3)
    878 {
    879 	return (kauth_authorize_action(kauth_builtin_scope_system, cred,
    880 	    action, (void *)req, arg1, arg2, arg3));
    881 }
    882 
    883 /*
    884  * Process scope authorization wrapper.
    885  */
    886 int
    887 kauth_authorize_process(kauth_cred_t cred, kauth_action_t action,
    888     struct proc *p, void *arg1, void *arg2, void *arg3)
    889 {
    890 	return (kauth_authorize_action(kauth_builtin_scope_process, cred,
    891 	    action, p, arg1, arg2, arg3));
    892 }
    893 
    894 /*
    895  * Network scope authorization wrapper.
    896  */
    897 int
    898 kauth_authorize_network(kauth_cred_t cred, kauth_action_t action,
    899     enum kauth_network_req req, void *arg1, void *arg2, void *arg3)
    900 {
    901 	return (kauth_authorize_action(kauth_builtin_scope_network, cred,
    902 	    action, (void *)req, arg1, arg2, arg3));
    903 }
    904 
    905 int
    906 kauth_authorize_machdep(kauth_cred_t cred, kauth_action_t action,
    907     void *arg0, void *arg1, void *arg2, void *arg3)
    908 {
    909 	return (kauth_authorize_action(kauth_builtin_scope_machdep, cred,
    910 	    action, arg0, arg1, arg2, arg3));
    911 }
    912 
    913 int
    914 kauth_authorize_device(kauth_cred_t cred, kauth_action_t action,
    915     void *arg0, void *arg1, void *arg2, void *arg3)
    916 {
    917 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    918 	    action, arg0, arg1, arg2, arg3));
    919 }
    920 
    921 int
    922 kauth_authorize_device_tty(kauth_cred_t cred, kauth_action_t action,
    923     struct tty *tty)
    924 {
    925 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    926 	    action, tty, NULL, NULL, NULL));
    927 }
    928 
    929 int
    930 kauth_authorize_device_spec(kauth_cred_t cred, enum kauth_device_req req,
    931     struct vnode *vp)
    932 {
    933 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    934 	    KAUTH_DEVICE_RAWIO_SPEC, (void *)req, vp, NULL, NULL));
    935 }
    936 
    937 int
    938 kauth_authorize_device_passthru(kauth_cred_t cred, dev_t dev, u_long bits,
    939     void *data)
    940 {
    941 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    942 	    KAUTH_DEVICE_RAWIO_PASSTHRU, (void *)bits, (void *)(u_long)dev,
    943 	    data, NULL));
    944 }
    945 
    946 static int
    947 kauth_cred_hook(kauth_cred_t cred, kauth_action_t action, void *arg0,
    948     void *arg1)
    949 {
    950 	int r;
    951 
    952 	r = kauth_authorize_action(kauth_builtin_scope_cred, cred, action,
    953 	    arg0, arg1, NULL, NULL);
    954 
    955 #ifdef DIAGNOSTIC
    956 	if (!SIMPLEQ_EMPTY(&kauth_builtin_scope_cred->listenq))
    957 		KASSERT(r == 0);
    958 #endif /* DIAGNOSTIC */
    959 
    960 	return (r);
    961 }
    962 
    963 void
    964 secmodel_register(void)
    965 {
    966 	KASSERT(nsecmodels + 1 != 0);
    967 
    968 	rw_enter(&kauth_lock, RW_WRITER);
    969 	nsecmodels++;
    970 	rw_exit(&kauth_lock);
    971 }
    972 
    973 void
    974 secmodel_deregister(void)
    975 {
    976 	KASSERT(nsecmodels != 0);
    977 
    978 	rw_enter(&kauth_lock, RW_WRITER);
    979 	nsecmodels--;
    980 	rw_exit(&kauth_lock);
    981 }
    982