xref: /netbsd-src/sys/kern/subr_acl_nfs4.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008-2010 Edward Tomasz Napierała <trasz@FreeBSD.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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * ACL support routines specific to NFSv4 access control lists.  These are
31  * utility routines for code common across file systems implementing NFSv4
32  * ACLs.
33  */
34 
35 #ifdef _KERNEL
36 #include <sys/cdefs.h>
37 #if 0
38 __FBSDID("$FreeBSD: head/sys/kern/subr_acl_nfs4.c 341827 2018-12-11 19:32:16Z mjg $");
39 #endif
40 __KERNEL_RCSID(0, "$NetBSD: subr_acl_nfs4.c,v 1.1 2020/05/16 18:31:50 christos Exp $");
41 
42 #include <sys/param.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/systm.h>
46 #include <sys/mount.h>
47 #include <sys/vnode.h>
48 #include <sys/errno.h>
49 #include <sys/stat.h>
50 #include <sys/sysctl.h>
51 #include <sys/acl.h>
52 #include <sys/kauth.h>
53 
54 static void	acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode);
55 
56 
57 #else
58 
59 #include <errno.h>
60 #include <assert.h>
61 #include <sys/acl.h>
62 #include <sys/stat.h>
63 #define KASSERT(a) assert(a)
64 
65 #endif /* !_KERNEL */
66 
67 #if 0
68 static int
69 _acl_entry_matches(struct acl_entry *ae, acl_tag_t tag, acl_perm_t perm,
70     acl_entry_type_t entry_type)
71 {
72 	if (ae->ae_tag != tag)
73 		return (0);
74 
75 	if (ae->ae_id != ACL_UNDEFINED_ID)
76 		return (0);
77 
78 	if (ae->ae_perm != perm)
79 		return (0);
80 
81 	if (ae->ae_entry_type != entry_type)
82 		return (0);
83 
84 	if (ae->ae_flags != 0)
85 		return (0);
86 
87 	return (1);
88 }
89 #endif
90 
91 static struct acl_entry *
92 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
93     acl_entry_type_t entry_type)
94 {
95 	struct acl_entry *ae;
96 
97 	KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES);
98 
99 	ae = &(aclp->acl_entry[aclp->acl_cnt]);
100 	aclp->acl_cnt++;
101 
102 	ae->ae_tag = tag;
103 	ae->ae_id = ACL_UNDEFINED_ID;
104 	ae->ae_perm = perm;
105 	ae->ae_entry_type = entry_type;
106 	ae->ae_flags = 0;
107 
108 	return (ae);
109 }
110 
111 #if 0
112 static struct acl_entry *
113 _acl_duplicate_entry(struct acl *aclp, unsigned int entry_index)
114 {
115 	size_t i;
116 
117 	KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES);
118 
119 	for (i = aclp->acl_cnt; i > entry_index; i--)
120 		aclp->acl_entry[i] = aclp->acl_entry[i - 1];
121 
122 	aclp->acl_cnt++;
123 
124 	return (&(aclp->acl_entry[entry_index + 1]));
125 }
126 #endif
127 
128 
129 #ifdef _KERNEL
130 void
131 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
132     int file_owner_id)
133 {
134 
135 	acl_nfs4_trivial_from_mode(aclp, mode);
136 }
137 #endif /* _KERNEL */
138 
139 void
140 __acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
141 {
142 	size_t i;
143 	mode_t old_mode = *_mode, mode = 0, seen = 0;
144 	const struct acl_entry *ae;
145 
146 	KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES);
147 
148 	/*
149 	 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
150 	 *
151 	 * 3.16.6.1. Recomputing mode upon SETATTR of ACL
152 	 */
153 
154 	for (i = 0; i < aclp->acl_cnt; i++) {
155 		ae = &(aclp->acl_entry[i]);
156 
157 		if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
158 		    ae->ae_entry_type != ACL_ENTRY_TYPE_DENY)
159 			continue;
160 
161 		if (ae->ae_flags & ACL_ENTRY_INHERIT_ONLY)
162 			continue;
163 
164 		if (ae->ae_tag == ACL_USER_OBJ) {
165 			if ((ae->ae_perm & ACL_READ_DATA) &&
166 			    ((seen & S_IRUSR) == 0)) {
167 				seen |= S_IRUSR;
168 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
169 					mode |= S_IRUSR;
170 			}
171 			if ((ae->ae_perm & ACL_WRITE_DATA) &&
172 			     ((seen & S_IWUSR) == 0)) {
173 				seen |= S_IWUSR;
174 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
175 					mode |= S_IWUSR;
176 			}
177 			if ((ae->ae_perm & ACL_EXECUTE) &&
178 			    ((seen & S_IXUSR) == 0)) {
179 				seen |= S_IXUSR;
180 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
181 					mode |= S_IXUSR;
182 			}
183 		} else if (ae->ae_tag == ACL_GROUP_OBJ) {
184 			if ((ae->ae_perm & ACL_READ_DATA) &&
185 			    ((seen & S_IRGRP) == 0)) {
186 				seen |= S_IRGRP;
187 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
188 					mode |= S_IRGRP;
189 			}
190 			if ((ae->ae_perm & ACL_WRITE_DATA) &&
191 			    ((seen & S_IWGRP) == 0)) {
192 				seen |= S_IWGRP;
193 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
194 					mode |= S_IWGRP;
195 			}
196 			if ((ae->ae_perm & ACL_EXECUTE) &&
197 			    ((seen & S_IXGRP) == 0)) {
198 				seen |= S_IXGRP;
199 				if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
200 					mode |= S_IXGRP;
201 			}
202 		} else if (ae->ae_tag == ACL_EVERYONE) {
203 			if (ae->ae_perm & ACL_READ_DATA) {
204 				if ((seen & S_IRUSR) == 0) {
205 					seen |= S_IRUSR;
206 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
207 						mode |= S_IRUSR;
208 				}
209 				if ((seen & S_IRGRP) == 0) {
210 					seen |= S_IRGRP;
211 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
212 						mode |= S_IRGRP;
213 				}
214 				if ((seen & S_IROTH) == 0) {
215 					seen |= S_IROTH;
216 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
217 						mode |= S_IROTH;
218 				}
219 			}
220 			if (ae->ae_perm & ACL_WRITE_DATA) {
221 				if ((seen & S_IWUSR) == 0) {
222 					seen |= S_IWUSR;
223 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
224 						mode |= S_IWUSR;
225 				}
226 				if ((seen & S_IWGRP) == 0) {
227 					seen |= S_IWGRP;
228 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
229 						mode |= S_IWGRP;
230 				}
231 				if ((seen & S_IWOTH) == 0) {
232 					seen |= S_IWOTH;
233 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
234 						mode |= S_IWOTH;
235 				}
236 			}
237 			if (ae->ae_perm & ACL_EXECUTE) {
238 				if ((seen & S_IXUSR) == 0) {
239 					seen |= S_IXUSR;
240 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
241 						mode |= S_IXUSR;
242 				}
243 				if ((seen & S_IXGRP) == 0) {
244 					seen |= S_IXGRP;
245 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
246 						mode |= S_IXGRP;
247 				}
248 				if ((seen & S_IXOTH) == 0) {
249 					seen |= S_IXOTH;
250 					if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
251 						mode |= S_IXOTH;
252 				}
253 			}
254 		}
255 	}
256 
257 	*_mode = mode | (old_mode & ACL_PRESERVE_MASK);
258 }
259 
260 /*
261  * Populate the ACL with entries inherited from parent_aclp.
262  */
263 static void
264 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
265     struct acl *child_aclp, mode_t mode, int file_owner_id,
266     int is_directory)
267 {
268 	int flags, tag;
269 	size_t i;
270 	const struct acl_entry *parent_entry;
271 	struct acl_entry *ae;
272 
273 	KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES);
274 
275 	for (i = 0; i < parent_aclp->acl_cnt; i++) {
276 		parent_entry = &(parent_aclp->acl_entry[i]);
277 		flags = parent_entry->ae_flags;
278 		tag = parent_entry->ae_tag;
279 
280 		/*
281 		 * Don't inherit owner@, group@, or everyone@ entries.
282 		 */
283 		if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
284 		    tag == ACL_EVERYONE)
285 			continue;
286 
287 		/*
288 		 * Entry is not inheritable at all.
289 		 */
290 		if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
291 		    ACL_ENTRY_FILE_INHERIT)) == 0)
292 			continue;
293 
294 		/*
295 		 * We're creating a file, but ae is not inheritable
296 		 * by files.
297 		 */
298 		if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
299 			continue;
300 
301 		/*
302 		 * Entry is inheritable only by files, but has NO_PROPAGATE
303 		 * flag set, and we're creating a directory, so it wouldn't
304 		 * propagate to any file in that directory anyway.
305 		 */
306 		if (is_directory &&
307 		    (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
308 		    (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
309 			continue;
310 
311 		/*
312 		 * Entry qualifies for being inherited.
313 		 */
314 		KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES);
315 		ae = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
316 		*ae = *parent_entry;
317 		child_aclp->acl_cnt++;
318 
319 		ae->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
320 		ae->ae_flags |= ACL_ENTRY_INHERITED;
321 
322 		/*
323 		 * If the type of the ACE is neither ALLOW nor DENY,
324 		 * then leave it as it is and proceed to the next one.
325 		 */
326 		if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
327 		    ae->ae_entry_type != ACL_ENTRY_TYPE_DENY)
328 			continue;
329 
330 		/*
331 		 * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
332 		 * the object being created is not a directory, then clear
333 		 * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
334 		 * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
335 		 * ACL_ENTRY_INHERIT_ONLY.
336 		 */
337 		if (ae->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
338 		    !is_directory) {
339 			ae->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
340 			ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
341 			ACL_ENTRY_INHERIT_ONLY);
342 		}
343 
344 		/*
345 		 * If the object is a directory and ACL_ENTRY_FILE_INHERIT
346 		 * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
347 		 * that ACL_ENTRY_INHERIT_ONLY is set.
348 		 */
349 		if (is_directory &&
350 		    (ae->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
351 		    ((ae->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
352 			ae->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
353 		}
354 
355 		if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
356 		    (ae->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
357 			/*
358 			 * Some permissions must never be inherited.
359 			 */
360 			ae->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
361 			    ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
362 
363 			/*
364 			 * Others must be masked according to the file mode.
365 			 */
366 			if ((mode & S_IRGRP) == 0)
367 				ae->ae_perm &= ~ACL_READ_DATA;
368 			if ((mode & S_IWGRP) == 0)
369 				ae->ae_perm &=
370 				    ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
371 			if ((mode & S_IXGRP) == 0)
372 				ae->ae_perm &= ~ACL_EXECUTE;
373 		}
374 	}
375 }
376 
377 /*
378  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
379  * It's also being used to calculate a trivial ACL, by inheriting from
380  * a NULL ACL.
381  */
382 static void
383 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
384     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
385 {
386 	acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
387 	acl_perm_t user_allow, group_allow, everyone_allow;
388 
389 	KASSERT(aclp->acl_cnt == 0);
390 
391 	user_allow = group_allow = everyone_allow = ACL_READ_ACL |
392 	    ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
393 	user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
394 	    ACL_WRITE_NAMED_ATTRS;
395 
396 	if (mode & S_IRUSR)
397 		user_allow |= ACL_READ_DATA;
398 	if (mode & S_IWUSR)
399 		user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
400 	if (mode & S_IXUSR)
401 		user_allow |= ACL_EXECUTE;
402 
403 	if (mode & S_IRGRP)
404 		group_allow |= ACL_READ_DATA;
405 	if (mode & S_IWGRP)
406 		group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
407 	if (mode & S_IXGRP)
408 		group_allow |= ACL_EXECUTE;
409 
410 	if (mode & S_IROTH)
411 		everyone_allow |= ACL_READ_DATA;
412 	if (mode & S_IWOTH)
413 		everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
414 	if (mode & S_IXOTH)
415 		everyone_allow |= ACL_EXECUTE;
416 
417 	user_deny = ((group_allow | everyone_allow) & ~user_allow);
418 	group_deny = everyone_allow & ~group_allow;
419 	user_allow_first = group_deny & ~user_deny;
420 
421 	if (user_allow_first != 0)
422 		_acl_append(aclp, ACL_USER_OBJ, user_allow_first,
423 		    ACL_ENTRY_TYPE_ALLOW);
424 	if (user_deny != 0)
425 		_acl_append(aclp, ACL_USER_OBJ, user_deny,
426 		    ACL_ENTRY_TYPE_DENY);
427 	if (group_deny != 0)
428 		_acl_append(aclp, ACL_GROUP_OBJ, group_deny,
429 		    ACL_ENTRY_TYPE_DENY);
430 
431 	if (parent_aclp != NULL)
432 		acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
433 		    file_owner_id, is_directory);
434 
435 	_acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
436 	_acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
437 	_acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
438 }
439 
440 #ifdef _KERNEL
441 void
442 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
443     struct acl *child_aclp, mode_t mode, int file_owner_id,
444     int is_directory)
445 {
446 
447 	acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
448 	    mode, file_owner_id, is_directory);
449 }
450 #endif /* _KERNEL */
451 
452 /*
453  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
454  * Note that this results in an ACL different from (but semantically
455  * equal to) the "canonical six" trivial ACL computed using algorithm
456  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
457  */
458 static void
459 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
460 {
461 
462 	aclp->acl_cnt = 0;
463 	acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
464 }
465 
466 #ifndef _KERNEL
467 /*
468  * This routine is used by libc to implement acl_strip_np(3)
469  * and acl_is_trivial_np(3).
470  */
471 void
472 __acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
473 {
474 
475 	aclp->acl_cnt = 0;
476 	acl_nfs4_trivial_from_mode(aclp, mode);
477 }
478 #endif /* !_KERNEL */
479 
480 #ifdef _KERNEL
481 static int
482 _acls_are_equal(const struct acl *a, const struct acl *b)
483 {
484 	int i;
485 	const struct acl_entry *entrya, *entryb;
486 
487 	if (a->acl_cnt != b->acl_cnt)
488 		return (0);
489 
490 	for (i = 0; i < b->acl_cnt; i++) {
491 		entrya = &(a->acl_entry[i]);
492 		entryb = &(b->acl_entry[i]);
493 
494 		if (entrya->ae_tag != entryb->ae_tag ||
495 		    entrya->ae_id != entryb->ae_id ||
496 		    entrya->ae_perm != entryb->ae_perm ||
497 		    entrya->ae_entry_type != entryb->ae_entry_type ||
498 		    entrya->ae_flags != entryb->ae_flags)
499 			return (0);
500 	}
501 
502 	return (1);
503 }
504 
505 /*
506  * This routine is used to determine whether to remove extended attribute
507  * that stores ACL contents.
508  */
509 int
510 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
511 {
512 	int trivial;
513 	mode_t tmpmode = 0;
514 	struct acl *tmpaclp;
515 
516 	if (aclp->acl_cnt > 6)
517 		return (0);
518 
519 	/*
520 	 * Compute the mode from the ACL, then compute new ACL from that mode.
521 	 * If the ACLs are identical, then the ACL is trivial.
522 	 *
523 	 * XXX: I guess there is a faster way to do this.  However, even
524 	 *      this slow implementation significantly speeds things up
525 	 *      for files that don't have non-trivial ACLs - it's critical
526 	 *      for performance to not use EA when they are not needed.
527 	 *
528 	 * First try the PSARC/2010/029 semantics.
529 	 */
530 	tmpaclp = acl_alloc(KM_SLEEP);
531 	__acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
532 	acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
533 	trivial = _acls_are_equal(aclp, tmpaclp);
534 	if (trivial) {
535 		acl_free(tmpaclp);
536 		return (trivial);
537 	}
538 
539 	/*
540 	 * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
541 	 */
542 	acl_free(tmpaclp);
543 
544 	return (trivial);
545 }
546 
547 int
548 acl_nfs4_check(const struct acl *aclp, int is_directory)
549 {
550 	size_t i;
551 	const struct acl_entry *ae;
552 
553 	/*
554 	 * The spec doesn't seem to say anything about ACL validity.
555 	 * It seems there is not much to do here.  There is even no need
556 	 * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
557 	 * entries, as there can be several of them and that's perfectly
558 	 * valid.  There can be none of them too.  Really.
559 	 */
560 
561 	if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
562 		return (EINVAL);
563 
564 	for (i = 0; i < aclp->acl_cnt; i++) {
565 		ae = &(aclp->acl_entry[i]);
566 
567 		switch (ae->ae_tag) {
568 		case ACL_USER_OBJ:
569 		case ACL_GROUP_OBJ:
570 		case ACL_EVERYONE:
571 			if (ae->ae_id != ACL_UNDEFINED_ID)
572 				return (EINVAL);
573 			break;
574 
575 		case ACL_USER:
576 		case ACL_GROUP:
577 			if (ae->ae_id == ACL_UNDEFINED_ID)
578 				return (EINVAL);
579 			break;
580 
581 		default:
582 			return (EINVAL);
583 		}
584 
585 		if ((ae->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
586 			return (EINVAL);
587 
588 		/*
589 		 * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
590 		 */
591 		if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
592 		    ae->ae_entry_type != ACL_ENTRY_TYPE_DENY)
593 			return (EINVAL);
594 
595 		if ((ae->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
596 			return (EINVAL);
597 
598 		/* Disallow unimplemented flags. */
599 		if (ae->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
600 		    ACL_ENTRY_FAILED_ACCESS))
601 			return (EINVAL);
602 
603 		/* Disallow flags not allowed for ordinary files. */
604 		if (!is_directory) {
605 			if (ae->ae_flags & (ACL_ENTRY_FILE_INHERIT |
606 			    ACL_ENTRY_DIRECTORY_INHERIT |
607 			    ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
608 				return (EINVAL);
609 		}
610 	}
611 
612 	return (0);
613 }
614 #endif
615