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kern_auth.c revision 1.46.4.1
      1 /* $NetBSD: kern_auth.c,v 1.46.4.1 2007/03/13 16:51:51 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 1.46.4.1 2007/03/13 16:51:51 ad Exp $");
     32 
     33 #include <sys/types.h>
     34 #include <sys/param.h>
     35 #include <sys/queue.h>
     36 #include <sys/proc.h>
     37 #include <sys/ucred.h>
     38 #include <sys/pool.h>
     39 #include <sys/kauth.h>
     40 #include <sys/kmem.h>
     41 #include <sys/rwlock.h>
     42 #include <sys/sysctl.h>		/* for pi_[p]cread */
     43 #include <sys/mutex.h>
     44 #include <sys/specificdata.h>
     45 
     46 /*
     47  * Secmodel-specific credentials.
     48  */
     49 struct kauth_key {
     50 	const char *ks_secmodel;	/* secmodel */
     51 	specificdata_key_t ks_key;	/* key */
     52 };
     53 
     54 /*
     55  * Credentials.
     56  *
     57  * A subset of this structure is used in kvm(3) (src/lib/libkvm/kvm_proc.c)
     58  * and should be synchronized with this structure when the update is
     59  * relevant.
     60  */
     61 struct kauth_cred {
     62 	kmutex_t cr_lock;		/* lock on cr_refcnt */
     63 	u_int cr_refcnt;		/* reference count */
     64 	uid_t cr_uid;			/* user id */
     65 	uid_t cr_euid;			/* effective user id */
     66 	uid_t cr_svuid;			/* saved effective user id */
     67 	gid_t cr_gid;			/* group id */
     68 	gid_t cr_egid;			/* effective group id */
     69 	gid_t cr_svgid;			/* saved effective group id */
     70 	u_int cr_ngroups;		/* number of groups */
     71 	gid_t cr_groups[NGROUPS];	/* group memberships */
     72 	specificdata_reference cr_sd;	/* specific data */
     73 };
     74 
     75 /*
     76  * Listener.
     77  */
     78 struct kauth_listener {
     79 	kauth_scope_callback_t		func;		/* callback */
     80 	kauth_scope_t			scope;		/* scope backpointer */
     81 	u_int				refcnt;		/* reference count */
     82 	SIMPLEQ_ENTRY(kauth_listener)	listener_next;	/* listener list */
     83 };
     84 
     85 /*
     86  * Scope.
     87  */
     88 struct kauth_scope {
     89 	const char		       *id;		/* scope name */
     90 	void			       *cookie;		/* user cookie */
     91 	u_int				nlisteners;	/* # of listeners */
     92 	SIMPLEQ_HEAD(, kauth_listener)	listenq;	/* listener list */
     93 	SIMPLEQ_ENTRY(kauth_scope)	next_scope;	/* scope list */
     94 };
     95 
     96 static int kauth_cred_hook(kauth_cred_t, kauth_action_t, void *, void *);
     97 
     98 static POOL_INIT(kauth_cred_pool, sizeof(struct kauth_cred), 0, 0, 0,
     99     "kauthcredpl", &pool_allocator_nointr, IPL_NONE);
    100 
    101 /* List of scopes and its lock. */
    102 static SIMPLEQ_HEAD(, kauth_scope) scope_list;
    103 
    104 /* Built-in scopes: generic, process. */
    105 static kauth_scope_t kauth_builtin_scope_generic;
    106 static kauth_scope_t kauth_builtin_scope_system;
    107 static kauth_scope_t kauth_builtin_scope_process;
    108 static kauth_scope_t kauth_builtin_scope_network;
    109 static kauth_scope_t kauth_builtin_scope_machdep;
    110 static kauth_scope_t kauth_builtin_scope_device;
    111 static kauth_scope_t kauth_builtin_scope_cred;
    112 
    113 static unsigned int nsecmodels = 0;
    114 
    115 static specificdata_domain_t kauth_domain;
    116 krwlock_t	kauth_lock;
    117 
    118 /* Allocate new, empty kauth credentials. */
    119 kauth_cred_t
    120 kauth_cred_alloc(void)
    121 {
    122 	kauth_cred_t cred;
    123 
    124 	cred = pool_get(&kauth_cred_pool, PR_WAITOK);
    125 	memset(cred, 0, sizeof(*cred));
    126 	mutex_init(&cred->cr_lock, MUTEX_DEFAULT, IPL_NONE);
    127 	cred->cr_refcnt = 1;
    128 	specificdata_init(kauth_domain, &cred->cr_sd);
    129 	kauth_cred_hook(cred, KAUTH_CRED_INIT, NULL, NULL);
    130 
    131 	return (cred);
    132 }
    133 
    134 /* Increment reference count to cred. */
    135 void
    136 kauth_cred_hold(kauth_cred_t cred)
    137 {
    138 	KASSERT(cred != NULL);
    139 	KASSERT(cred->cr_refcnt > 0);
    140 
    141         mutex_enter(&cred->cr_lock);
    142         cred->cr_refcnt++;
    143         mutex_exit(&cred->cr_lock);
    144 }
    145 
    146 /* Decrease reference count to cred. If reached zero, free it. */
    147 void
    148 kauth_cred_free(kauth_cred_t cred)
    149 {
    150 	u_int refcnt;
    151 
    152 	KASSERT(cred != NULL);
    153 	KASSERT(cred->cr_refcnt > 0);
    154 
    155 	mutex_enter(&cred->cr_lock);
    156 	refcnt = --cred->cr_refcnt;
    157 	mutex_exit(&cred->cr_lock);
    158 
    159 	if (refcnt == 0) {
    160 		kauth_cred_hook(cred, KAUTH_CRED_FREE, NULL, NULL);
    161 		specificdata_fini(kauth_domain, &cred->cr_sd);
    162 		mutex_destroy(&cred->cr_lock);
    163 		pool_put(&kauth_cred_pool, cred);
    164 	}
    165 }
    166 
    167 void
    168 kauth_cred_clone(kauth_cred_t from, kauth_cred_t to)
    169 {
    170 	KASSERT(from != NULL);
    171 	KASSERT(to != NULL);
    172 	KASSERT(from->cr_refcnt > 0);
    173 
    174 	to->cr_uid = from->cr_uid;
    175 	to->cr_euid = from->cr_euid;
    176 	to->cr_svuid = from->cr_svuid;
    177 	to->cr_gid = from->cr_gid;
    178 	to->cr_egid = from->cr_egid;
    179 	to->cr_svgid = from->cr_svgid;
    180 	to->cr_ngroups = from->cr_ngroups;
    181 	memcpy(to->cr_groups, from->cr_groups, sizeof(to->cr_groups));
    182 
    183 	kauth_cred_hook(from, KAUTH_CRED_COPY, to, NULL);
    184 }
    185 
    186 /*
    187  * Duplicate cred and return a new kauth_cred_t.
    188  */
    189 kauth_cred_t
    190 kauth_cred_dup(kauth_cred_t cred)
    191 {
    192 	kauth_cred_t new_cred;
    193 
    194 	KASSERT(cred != NULL);
    195 	KASSERT(cred->cr_refcnt > 0);
    196 
    197 	new_cred = kauth_cred_alloc();
    198 
    199 	kauth_cred_clone(cred, new_cred);
    200 
    201 	return (new_cred);
    202 }
    203 
    204 /*
    205  * Similar to crcopy(), only on a kauth_cred_t.
    206  * XXX: Is this even needed? [kauth_cred_copy]
    207  */
    208 kauth_cred_t
    209 kauth_cred_copy(kauth_cred_t cred)
    210 {
    211 	kauth_cred_t new_cred;
    212 
    213 	KASSERT(cred != NULL);
    214 	KASSERT(cred->cr_refcnt > 0);
    215 
    216 	/* If the provided credentials already have one reference, use them. */
    217 	if (cred->cr_refcnt == 1)
    218 		return (cred);
    219 
    220 	new_cred = kauth_cred_alloc();
    221 
    222 	kauth_cred_clone(cred, new_cred);
    223 
    224 	kauth_cred_free(cred);
    225 
    226 	return (new_cred);
    227 }
    228 
    229 void
    230 kauth_proc_fork(struct proc *parent, struct proc *child)
    231 {
    232 
    233 	mutex_enter(&parent->p_mutex);
    234 	kauth_cred_hold(parent->p_cred);
    235 	child->p_cred = parent->p_cred;
    236 	mutex_exit(&parent->p_mutex);
    237 
    238 	/* XXX: relies on parent process stalling during fork() */
    239 	kauth_cred_hook(parent->p_cred, KAUTH_CRED_FORK, parent,
    240 	    child);
    241 }
    242 
    243 uid_t
    244 kauth_cred_getuid(kauth_cred_t cred)
    245 {
    246 	KASSERT(cred != NULL);
    247 
    248 	return (cred->cr_uid);
    249 }
    250 
    251 uid_t
    252 kauth_cred_geteuid(kauth_cred_t cred)
    253 {
    254 	KASSERT(cred != NULL);
    255 
    256 	return (cred->cr_euid);
    257 }
    258 
    259 uid_t
    260 kauth_cred_getsvuid(kauth_cred_t cred)
    261 {
    262 	KASSERT(cred != NULL);
    263 
    264 	return (cred->cr_svuid);
    265 }
    266 
    267 gid_t
    268 kauth_cred_getgid(kauth_cred_t cred)
    269 {
    270 	KASSERT(cred != NULL);
    271 
    272 	return (cred->cr_gid);
    273 }
    274 
    275 gid_t
    276 kauth_cred_getegid(kauth_cred_t cred)
    277 {
    278 	KASSERT(cred != NULL);
    279 
    280 	return (cred->cr_egid);
    281 }
    282 
    283 gid_t
    284 kauth_cred_getsvgid(kauth_cred_t cred)
    285 {
    286 	KASSERT(cred != NULL);
    287 
    288 	return (cred->cr_svgid);
    289 }
    290 
    291 void
    292 kauth_cred_setuid(kauth_cred_t cred, uid_t uid)
    293 {
    294 	KASSERT(cred != NULL);
    295 	KASSERT(cred->cr_refcnt == 1);
    296 
    297 	cred->cr_uid = uid;
    298 }
    299 
    300 void
    301 kauth_cred_seteuid(kauth_cred_t cred, uid_t uid)
    302 {
    303 	KASSERT(cred != NULL);
    304 	KASSERT(cred->cr_refcnt == 1);
    305 
    306 	cred->cr_euid = uid;
    307 }
    308 
    309 void
    310 kauth_cred_setsvuid(kauth_cred_t cred, uid_t uid)
    311 {
    312 	KASSERT(cred != NULL);
    313 	KASSERT(cred->cr_refcnt == 1);
    314 
    315 	cred->cr_svuid = uid;
    316 }
    317 
    318 void
    319 kauth_cred_setgid(kauth_cred_t cred, gid_t gid)
    320 {
    321 	KASSERT(cred != NULL);
    322 	KASSERT(cred->cr_refcnt == 1);
    323 
    324 	cred->cr_gid = gid;
    325 }
    326 
    327 void
    328 kauth_cred_setegid(kauth_cred_t cred, gid_t gid)
    329 {
    330 	KASSERT(cred != NULL);
    331 	KASSERT(cred->cr_refcnt == 1);
    332 
    333 	cred->cr_egid = gid;
    334 }
    335 
    336 void
    337 kauth_cred_setsvgid(kauth_cred_t cred, gid_t gid)
    338 {
    339 	KASSERT(cred != NULL);
    340 	KASSERT(cred->cr_refcnt == 1);
    341 
    342 	cred->cr_svgid = gid;
    343 }
    344 
    345 /* Checks if gid is a member of the groups in cred. */
    346 int
    347 kauth_cred_ismember_gid(kauth_cred_t cred, gid_t gid, int *resultp)
    348 {
    349 	int i;
    350 
    351 	KASSERT(cred != NULL);
    352 	KASSERT(resultp != NULL);
    353 
    354 	*resultp = 0;
    355 
    356 	for (i = 0; i < cred->cr_ngroups; i++)
    357 		if (cred->cr_groups[i] == gid) {
    358 			*resultp = 1;
    359 			break;
    360 		}
    361 
    362 	return (0);
    363 }
    364 
    365 u_int
    366 kauth_cred_ngroups(kauth_cred_t cred)
    367 {
    368 	KASSERT(cred != NULL);
    369 
    370 	return (cred->cr_ngroups);
    371 }
    372 
    373 /*
    374  * Return the group at index idx from the groups in cred.
    375  */
    376 gid_t
    377 kauth_cred_group(kauth_cred_t cred, u_int idx)
    378 {
    379 	KASSERT(cred != NULL);
    380 	KASSERT(idx < cred->cr_ngroups);
    381 
    382 	return (cred->cr_groups[idx]);
    383 }
    384 
    385 /* XXX elad: gmuid is unused for now. */
    386 int
    387 kauth_cred_setgroups(kauth_cred_t cred, gid_t *grbuf, size_t len, uid_t gmuid)
    388 {
    389 	KASSERT(cred != NULL);
    390 	KASSERT(cred->cr_refcnt == 1);
    391 	KASSERT(len <= sizeof(cred->cr_groups) / sizeof(cred->cr_groups[0]));
    392 
    393 	if (len)
    394 		memcpy(cred->cr_groups, grbuf, len * sizeof(cred->cr_groups[0]));
    395 	memset(cred->cr_groups + len, 0xff,
    396 	    sizeof(cred->cr_groups) - (len * sizeof(cred->cr_groups[0])));
    397 
    398 	cred->cr_ngroups = len;
    399 
    400 	return (0);
    401 }
    402 
    403 int
    404 kauth_cred_getgroups(kauth_cred_t cred, gid_t *grbuf, size_t len)
    405 {
    406 	KASSERT(cred != NULL);
    407 	KASSERT(len <= cred->cr_ngroups);
    408 
    409 	memset(grbuf, 0xff, sizeof(*grbuf) * len);
    410 	memcpy(grbuf, cred->cr_groups, sizeof(*grbuf) * len);
    411 
    412 	return (0);
    413 }
    414 
    415 int
    416 kauth_register_key(const char *secmodel, kauth_key_t *result)
    417 {
    418 	kauth_key_t k;
    419 	specificdata_key_t key;
    420 	int error;
    421 
    422 	KASSERT(result != NULL);
    423 
    424 	error = specificdata_key_create(kauth_domain, &key, NULL);
    425 	if (error)
    426 		return (error);
    427 
    428 	k = kmem_alloc(sizeof(*k), KM_SLEEP);
    429 	k->ks_secmodel = secmodel;
    430 	k->ks_key = key;
    431 
    432 	*result = k;
    433 
    434 	return (0);
    435 }
    436 
    437 int
    438 kauth_deregister_key(kauth_key_t key)
    439 {
    440 	KASSERT(key != NULL);
    441 
    442 	specificdata_key_delete(kauth_domain, key->ks_key);
    443 	kmem_free(key, sizeof(*key));
    444 
    445 	return (0);
    446 }
    447 
    448 void *
    449 kauth_cred_getdata(kauth_cred_t cred, kauth_key_t key)
    450 {
    451 	KASSERT(cred != NULL);
    452 	KASSERT(key != NULL);
    453 
    454 	return (specificdata_getspecific(kauth_domain, &cred->cr_sd,
    455 	    key->ks_key));
    456 }
    457 
    458 void
    459 kauth_cred_setdata(kauth_cred_t cred, kauth_key_t key, void *data)
    460 {
    461 	KASSERT(cred != NULL);
    462 	KASSERT(key != NULL);
    463 
    464 	specificdata_setspecific(kauth_domain, &cred->cr_sd, key->ks_key, data);
    465 }
    466 
    467 /*
    468  * Match uids in two credentials.
    469  */
    470 int
    471 kauth_cred_uidmatch(kauth_cred_t cred1, kauth_cred_t cred2)
    472 {
    473 	KASSERT(cred1 != NULL);
    474 	KASSERT(cred2 != NULL);
    475 
    476 	if (cred1->cr_uid == cred2->cr_uid ||
    477 	    cred1->cr_euid == cred2->cr_uid ||
    478 	    cred1->cr_uid == cred2->cr_euid ||
    479 	    cred1->cr_euid == cred2->cr_euid)
    480 		return (1);
    481 
    482 	return (0);
    483 }
    484 
    485 u_int
    486 kauth_cred_getrefcnt(kauth_cred_t cred)
    487 {
    488 	KASSERT(cred != NULL);
    489 
    490 	return (cred->cr_refcnt);
    491 }
    492 
    493 /*
    494  * Convert userland credentials (struct uucred) to kauth_cred_t.
    495  * XXX: For NFS & puffs
    496  */
    497 void
    498 kauth_uucred_to_cred(kauth_cred_t cred, const struct uucred *uuc)
    499 {
    500 	KASSERT(cred != NULL);
    501 	KASSERT(uuc != NULL);
    502 
    503 	cred->cr_refcnt = 1;
    504 	cred->cr_uid = uuc->cr_uid;
    505 	cred->cr_euid = uuc->cr_uid;
    506 	cred->cr_svuid = uuc->cr_uid;
    507 	cred->cr_gid = uuc->cr_gid;
    508 	cred->cr_egid = uuc->cr_gid;
    509 	cred->cr_svgid = uuc->cr_gid;
    510 	cred->cr_ngroups = min(uuc->cr_ngroups, NGROUPS);
    511 	kauth_cred_setgroups(cred, __UNCONST(uuc->cr_groups),
    512 	    cred->cr_ngroups, -1);
    513 }
    514 
    515 /*
    516  * Convert kauth_cred_t to userland credentials (struct uucred).
    517  * XXX: For NFS & puffs
    518  */
    519 void
    520 kauth_cred_to_uucred(struct uucred *uuc, const kauth_cred_t cred)
    521 {
    522 	KASSERT(cred != NULL);
    523 	KASSERT(uuc != NULL);
    524 	int ng;
    525 
    526 	ng = min(cred->cr_ngroups, NGROUPS);
    527 	uuc->cr_uid = cred->cr_euid;
    528 	uuc->cr_gid = cred->cr_egid;
    529 	uuc->cr_ngroups = ng;
    530 	kauth_cred_getgroups(cred, uuc->cr_groups, ng);
    531 }
    532 
    533 /*
    534  * Compare kauth_cred_t and uucred credentials.
    535  * XXX: Modelled after crcmp() for NFS.
    536  */
    537 int
    538 kauth_cred_uucmp(kauth_cred_t cred, const struct uucred *uuc)
    539 {
    540 	KASSERT(cred != NULL);
    541 	KASSERT(uuc != NULL);
    542 
    543 	if (cred->cr_euid == uuc->cr_uid &&
    544 	    cred->cr_egid == uuc->cr_gid &&
    545 	    cred->cr_ngroups == uuc->cr_ngroups) {
    546 		int i;
    547 
    548 		/* Check if all groups from uuc appear in cred. */
    549 		for (i = 0; i < uuc->cr_ngroups; i++) {
    550 			int ismember;
    551 
    552 			ismember = 0;
    553 			if (kauth_cred_ismember_gid(cred, uuc->cr_groups[i],
    554 			    &ismember) != 0 || !ismember)
    555 				return (1);
    556 		}
    557 
    558 		return (0);
    559 	}
    560 
    561 	return (1);
    562 }
    563 
    564 /*
    565  * Make a struct ucred out of a kauth_cred_t.  For compatibility.
    566  */
    567 void
    568 kauth_cred_toucred(kauth_cred_t cred, struct ki_ucred *uc)
    569 {
    570 	KASSERT(cred != NULL);
    571 	KASSERT(uc != NULL);
    572 
    573 	uc->cr_ref = cred->cr_refcnt;
    574 	uc->cr_uid = cred->cr_euid;
    575 	uc->cr_gid = cred->cr_egid;
    576 	uc->cr_ngroups = min(cred->cr_ngroups,
    577 			     sizeof(uc->cr_groups) / sizeof(uc->cr_groups[0]));
    578 	memcpy(uc->cr_groups, cred->cr_groups,
    579 	       uc->cr_ngroups * sizeof(uc->cr_groups[0]));
    580 }
    581 
    582 /*
    583  * Make a struct pcred out of a kauth_cred_t.  For compatibility.
    584  */
    585 void
    586 kauth_cred_topcred(kauth_cred_t cred, struct ki_pcred *pc)
    587 {
    588 	KASSERT(cred != NULL);
    589 	KASSERT(pc != NULL);
    590 
    591 	pc->p_pad = NULL;
    592 	pc->p_ruid = cred->cr_uid;
    593 	pc->p_svuid = cred->cr_svuid;
    594 	pc->p_rgid = cred->cr_gid;
    595 	pc->p_svgid = cred->cr_svgid;
    596 	pc->p_refcnt = cred->cr_refcnt;
    597 }
    598 
    599 /*
    600  * Return kauth_cred_t for the current LWP.
    601  */
    602 kauth_cred_t
    603 kauth_cred_get(void)
    604 {
    605 	return (curlwp->l_cred);
    606 }
    607 
    608 /*
    609  * Returns a scope matching the provided id.
    610  * Requires the scope list lock to be held by the caller.
    611  */
    612 static kauth_scope_t
    613 kauth_ifindscope(const char *id)
    614 {
    615 	kauth_scope_t scope;
    616 
    617 	KASSERT(rw_lock_held(&kauth_lock));
    618 
    619 	scope = NULL;
    620 	SIMPLEQ_FOREACH(scope, &scope_list, next_scope) {
    621 		if (strcmp(scope->id, id) == 0)
    622 			break;
    623 	}
    624 
    625 	return (scope);
    626 }
    627 
    628 /*
    629  * Register a new scope.
    630  *
    631  * id - identifier for the scope
    632  * callback - the scope's default listener
    633  * cookie - cookie to be passed to the listener(s)
    634  */
    635 kauth_scope_t
    636 kauth_register_scope(const char *id, kauth_scope_callback_t callback,
    637     void *cookie)
    638 {
    639 	kauth_scope_t scope;
    640 	kauth_listener_t listener = NULL; /* XXX gcc */
    641 
    642 	/* Sanitize input */
    643 	if (id == NULL)
    644 		return (NULL);
    645 
    646 	/* Allocate space for a new scope and listener. */
    647 	scope = kmem_alloc(sizeof(*scope), KM_SLEEP);
    648 	if (scope == NULL)
    649 		return NULL;
    650 	if (callback != NULL) {
    651 		listener = kmem_alloc(sizeof(*listener), KM_SLEEP);
    652 		if (listener == NULL) {
    653 			kmem_free(scope, sizeof(*scope));
    654 			return (NULL);
    655 		}
    656 	}
    657 
    658 	/*
    659 	 * Acquire scope list lock.
    660 	 */
    661 	rw_enter(&kauth_lock, RW_WRITER);
    662 
    663 	/* Check we don't already have a scope with the same id */
    664 	if (kauth_ifindscope(id) != NULL) {
    665 		rw_exit(&kauth_lock);
    666 
    667 		kmem_free(scope, sizeof(*scope));
    668 		if (callback != NULL)
    669 			kmem_free(listener, sizeof(*listener));
    670 
    671 		return (NULL);
    672 	}
    673 
    674 	/* Initialize new scope with parameters */
    675 	scope->id = id;
    676 	scope->cookie = cookie;
    677 	scope->nlisteners = 1;
    678 
    679 	SIMPLEQ_INIT(&scope->listenq);
    680 
    681 	/* Add default listener */
    682 	if (callback != NULL) {
    683 		listener->func = callback;
    684 		listener->scope = scope;
    685 		listener->refcnt = 0;
    686 		SIMPLEQ_INSERT_HEAD(&scope->listenq, listener, listener_next);
    687 	}
    688 
    689 	/* Insert scope to scopes list */
    690 	SIMPLEQ_INSERT_TAIL(&scope_list, scope, next_scope);
    691 
    692 	rw_exit(&kauth_lock);
    693 
    694 	return (scope);
    695 }
    696 
    697 /*
    698  * Initialize the kernel authorization subsystem.
    699  *
    700  * Initialize the scopes list lock.
    701  * Create specificdata domain.
    702  * Register the credentials scope, used in kauth(9) internally.
    703  * Register built-in scopes: generic, system, process, network, machdep, device.
    704  */
    705 void
    706 kauth_init(void)
    707 {
    708 	SIMPLEQ_INIT(&scope_list);
    709 	rw_init(&kauth_lock);
    710 
    711 	/* Create specificdata domain. */
    712 	kauth_domain = specificdata_domain_create();
    713 
    714 	/* Register credentials scope. */
    715 	kauth_builtin_scope_cred =
    716 	    kauth_register_scope(KAUTH_SCOPE_CRED, NULL, NULL);
    717 
    718 	/* Register generic scope. */
    719 	kauth_builtin_scope_generic = kauth_register_scope(KAUTH_SCOPE_GENERIC,
    720 	    NULL, NULL);
    721 
    722 	/* Register system scope. */
    723 	kauth_builtin_scope_system = kauth_register_scope(KAUTH_SCOPE_SYSTEM,
    724 	    NULL, NULL);
    725 
    726 	/* Register process scope. */
    727 	kauth_builtin_scope_process = kauth_register_scope(KAUTH_SCOPE_PROCESS,
    728 	    NULL, NULL);
    729 
    730 	/* Register network scope. */
    731 	kauth_builtin_scope_network = kauth_register_scope(KAUTH_SCOPE_NETWORK,
    732 	    NULL, NULL);
    733 
    734 	/* Register machdep scope. */
    735 	kauth_builtin_scope_machdep = kauth_register_scope(KAUTH_SCOPE_MACHDEP,
    736 	    NULL, NULL);
    737 
    738 	/* Register device scope. */
    739 	kauth_builtin_scope_device = kauth_register_scope(KAUTH_SCOPE_DEVICE,
    740 	    NULL, NULL);
    741 }
    742 
    743 /*
    744  * Deregister a scope.
    745  * Requires scope list lock to be held by the caller.
    746  *
    747  * scope - the scope to deregister
    748  */
    749 void
    750 kauth_deregister_scope(kauth_scope_t scope)
    751 {
    752 	if (scope != NULL) {
    753 		/* Remove scope from list */
    754 		SIMPLEQ_REMOVE(&scope_list, scope, kauth_scope, next_scope);
    755 		kmem_free(scope, sizeof(*scope));
    756 	}
    757 }
    758 
    759 /*
    760  * Register a listener.
    761  *
    762  * id - scope identifier.
    763  * callback - the callback routine for the listener.
    764  * cookie - cookie to pass unmoidfied to the callback.
    765  */
    766 kauth_listener_t
    767 kauth_listen_scope(const char *id, kauth_scope_callback_t callback,
    768    void *cookie)
    769 {
    770 	kauth_scope_t scope;
    771 	kauth_listener_t listener;
    772 
    773 	listener = kmem_alloc(sizeof(*listener), KM_SLEEP);
    774 	if (listener == NULL)
    775 		return (NULL);
    776 
    777 	rw_enter(&kauth_lock, RW_WRITER);
    778 
    779 	/*
    780 	 * Find scope struct.
    781 	 */
    782 	scope = kauth_ifindscope(id);
    783 	if (scope == NULL) {
    784 		rw_exit(&kauth_lock);
    785 		kmem_free(listener, sizeof(*listener));
    786 		return (NULL);
    787 	}
    788 
    789 	/* Allocate listener */
    790 
    791 	/* Initialize listener with parameters */
    792 	listener->func = callback;
    793 	listener->refcnt = 0;
    794 
    795 	/* Add listener to scope */
    796 	SIMPLEQ_INSERT_TAIL(&scope->listenq, listener, listener_next);
    797 
    798 	/* Raise number of listeners on scope. */
    799 	scope->nlisteners++;
    800 	listener->scope = scope;
    801 
    802 	rw_exit(&kauth_lock);
    803 
    804 	return (listener);
    805 }
    806 
    807 /*
    808  * Deregister a listener.
    809  *
    810  * listener - listener reference as returned from kauth_listen_scope().
    811  */
    812 void
    813 kauth_unlisten_scope(kauth_listener_t listener)
    814 {
    815 
    816 	if (listener != NULL) {
    817 		rw_enter(&kauth_lock, RW_WRITER);
    818 		SIMPLEQ_REMOVE(&listener->scope->listenq, listener,
    819 		    kauth_listener, listener_next);
    820 		listener->scope->nlisteners--;
    821 		rw_exit(&kauth_lock);
    822 		kmem_free(listener, sizeof(*listener));
    823 	}
    824 }
    825 
    826 /*
    827  * Authorize a request.
    828  *
    829  * scope - the scope of the request as defined by KAUTH_SCOPE_* or as
    830  *	   returned from kauth_register_scope().
    831  * credential - credentials of the user ("actor") making the request.
    832  * action - request identifier.
    833  * arg[0-3] - passed unmodified to listener(s).
    834  */
    835 int
    836 kauth_authorize_action(kauth_scope_t scope, kauth_cred_t cred,
    837 		       kauth_action_t action, void *arg0, void *arg1,
    838 		       void *arg2, void *arg3)
    839 {
    840 	kauth_listener_t listener;
    841 	int error, allow, fail;
    842 
    843 #if 0 /* defined(LOCKDEBUG) */
    844 	spinlock_switchcheck();
    845 	simple_lock_only_held(NULL, "kauth_authorize_action");
    846 #endif
    847 
    848 	KASSERT(cred != NULL);
    849 	KASSERT(action != 0);
    850 
    851 	/* Short-circuit requests coming from the kernel. */
    852 	if (cred == NOCRED || cred == FSCRED)
    853 		return (0);
    854 
    855 	KASSERT(scope != NULL);
    856 
    857 	fail = 0;
    858 	allow = 0;
    859 
    860 	/* rw_enter(&kauth_lock, RW_READER); XXX not yet */
    861 	SIMPLEQ_FOREACH(listener, &scope->listenq, listener_next) {
    862 		error = listener->func(cred, action, scope->cookie, arg0,
    863 		    arg1, arg2, arg3);
    864 
    865 		if (error == KAUTH_RESULT_ALLOW)
    866 			allow = 1;
    867 		else if (error == KAUTH_RESULT_DENY)
    868 			fail = 1;
    869 	}
    870 	/* rw_exit(&kauth_lock); */
    871 
    872 	if (fail)
    873 		return (EPERM);
    874 
    875 	if (allow)
    876 		return (0);
    877 
    878 	if (!nsecmodels)
    879 		return (0);
    880 
    881 	return (EPERM);
    882 };
    883 
    884 /*
    885  * Generic scope authorization wrapper.
    886  */
    887 int
    888 kauth_authorize_generic(kauth_cred_t cred, kauth_action_t action, void *arg0)
    889 {
    890 	return (kauth_authorize_action(kauth_builtin_scope_generic, cred,
    891 	    action, arg0, NULL, NULL, NULL));
    892 }
    893 
    894 /*
    895  * System scope authorization wrapper.
    896  */
    897 int
    898 kauth_authorize_system(kauth_cred_t cred, kauth_action_t action,
    899     enum kauth_system_req req, void *arg1, void *arg2, void *arg3)
    900 {
    901 	return (kauth_authorize_action(kauth_builtin_scope_system, cred,
    902 	    action, (void *)req, arg1, arg2, arg3));
    903 }
    904 
    905 /*
    906  * Process scope authorization wrapper.
    907  */
    908 int
    909 kauth_authorize_process(kauth_cred_t cred, kauth_action_t action,
    910     struct proc *p, void *arg1, void *arg2, void *arg3)
    911 {
    912 	return (kauth_authorize_action(kauth_builtin_scope_process, cred,
    913 	    action, p, arg1, arg2, arg3));
    914 }
    915 
    916 /*
    917  * Network scope authorization wrapper.
    918  */
    919 int
    920 kauth_authorize_network(kauth_cred_t cred, kauth_action_t action,
    921     enum kauth_network_req req, void *arg1, void *arg2, void *arg3)
    922 {
    923 	return (kauth_authorize_action(kauth_builtin_scope_network, cred,
    924 	    action, (void *)req, arg1, arg2, arg3));
    925 }
    926 
    927 int
    928 kauth_authorize_machdep(kauth_cred_t cred, kauth_action_t action,
    929     void *arg0, void *arg1, void *arg2, void *arg3)
    930 {
    931 	return (kauth_authorize_action(kauth_builtin_scope_machdep, cred,
    932 	    action, arg0, arg1, arg2, arg3));
    933 }
    934 
    935 int
    936 kauth_authorize_device(kauth_cred_t cred, kauth_action_t action,
    937     void *arg0, void *arg1, void *arg2, void *arg3)
    938 {
    939 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    940 	    action, arg0, arg1, arg2, arg3));
    941 }
    942 
    943 int
    944 kauth_authorize_device_tty(kauth_cred_t cred, kauth_action_t action,
    945     struct tty *tty)
    946 {
    947 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    948 	    action, tty, NULL, NULL, NULL));
    949 }
    950 
    951 int
    952 kauth_authorize_device_spec(kauth_cred_t cred, enum kauth_device_req req,
    953     struct vnode *vp)
    954 {
    955 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    956 	    KAUTH_DEVICE_RAWIO_SPEC, (void *)req, vp, NULL, NULL));
    957 }
    958 
    959 int
    960 kauth_authorize_device_passthru(kauth_cred_t cred, dev_t dev, u_long bits,
    961     void *data)
    962 {
    963 	return (kauth_authorize_action(kauth_builtin_scope_device, cred,
    964 	    KAUTH_DEVICE_RAWIO_PASSTHRU, (void *)bits, (void *)(u_long)dev,
    965 	    data, NULL));
    966 }
    967 
    968 static int
    969 kauth_cred_hook(kauth_cred_t cred, kauth_action_t action, void *arg0,
    970     void *arg1)
    971 {
    972 	int r;
    973 
    974 	r = kauth_authorize_action(kauth_builtin_scope_cred, cred, action,
    975 	    arg0, arg1, NULL, NULL);
    976 
    977 #ifdef DIAGNOSTIC
    978 	if (!SIMPLEQ_EMPTY(&kauth_builtin_scope_cred->listenq))
    979 		KASSERT(r == 0);
    980 #endif /* DIAGNOSTIC */
    981 
    982 	return (r);
    983 }
    984 
    985 void
    986 secmodel_register(void)
    987 {
    988 	KASSERT(nsecmodels + 1 != 0);
    989 
    990 	rw_enter(&kauth_lock, RW_WRITER);
    991 	nsecmodels++;
    992 	rw_exit(&kauth_lock);
    993 }
    994 
    995 void
    996 secmodel_deregister(void)
    997 {
    998 	KASSERT(nsecmodels != 0);
    999 
   1000 	rw_enter(&kauth_lock, RW_WRITER);
   1001 	nsecmodels--;
   1002 	rw_exit(&kauth_lock);
   1003 }
   1004