subr_acl_nfs4.c revision 219880
1/*-
2 * Copyright (c) 2008-2010 Edward Tomasz Napiera��a <trasz@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * ACL support routines specific to NFSv4 access control lists.  These are
29 * utility routines for code common across file systems implementing NFSv4
30 * ACLs.
31 */
32
33#ifdef _KERNEL
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: head/sys/kern/subr_acl_nfs4.c 219880 2011-03-22 19:52:29Z trasz $");
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/mount.h>
40#include <sys/priv.h>
41#include <sys/vnode.h>
42#include <sys/errno.h>
43#include <sys/stat.h>
44#include <sys/sysctl.h>
45#include <sys/acl.h>
46#else
47#include <errno.h>
48#include <assert.h>
49#include <sys/acl.h>
50#include <sys/stat.h>
51#define KASSERT(a, b) assert(a)
52#define CTASSERT(a)
53
54#endif /* !_KERNEL */
55
56#ifdef _KERNEL
57
58static void	acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode);
59
60static int	acl_nfs4_old_semantics = 0;
61
62SYSCTL_INT(_vfs, OID_AUTO, acl_nfs4_old_semantics, CTLFLAG_RW,
63    &acl_nfs4_old_semantics, 0, "Use pre-PSARC/2010/029 NFSv4 ACL semantics");
64
65static struct {
66	accmode_t accmode;
67	int mask;
68} accmode2mask[] = {{VREAD, ACL_READ_DATA},
69		    {VWRITE, ACL_WRITE_DATA},
70		    {VAPPEND, ACL_APPEND_DATA},
71		    {VEXEC, ACL_EXECUTE},
72		    {VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
73		    {VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
74		    {VDELETE_CHILD, ACL_DELETE_CHILD},
75		    {VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
76		    {VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
77		    {VDELETE, ACL_DELETE},
78		    {VREAD_ACL, ACL_READ_ACL},
79		    {VWRITE_ACL, ACL_WRITE_ACL},
80		    {VWRITE_OWNER, ACL_WRITE_OWNER},
81		    {VSYNCHRONIZE, ACL_SYNCHRONIZE},
82		    {0, 0}};
83
84static int
85_access_mask_from_accmode(accmode_t accmode)
86{
87	int access_mask = 0, i;
88
89	for (i = 0; accmode2mask[i].accmode != 0; i++) {
90		if (accmode & accmode2mask[i].accmode)
91			access_mask |= accmode2mask[i].mask;
92	}
93
94	/*
95	 * VAPPEND is just a modifier for VWRITE; if the caller asked
96	 * for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
97	 */
98	if (access_mask & ACL_APPEND_DATA)
99		access_mask &= ~ACL_WRITE_DATA;
100
101	return (access_mask);
102}
103
104/*
105 * Return 0, iff access is allowed, 1 otherwise.
106 */
107static int
108_acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
109    int file_uid, int file_gid, int *denied_explicitly)
110{
111	int i;
112	const struct acl_entry *entry;
113
114	if (denied_explicitly != NULL)
115		*denied_explicitly = 0;
116
117	KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
118	KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
119	    ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
120
121	for (i = 0; i < aclp->acl_cnt; i++) {
122		entry = &(aclp->acl_entry[i]);
123
124		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
125		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
126			continue;
127		if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
128			continue;
129		switch (entry->ae_tag) {
130		case ACL_USER_OBJ:
131			if (file_uid != cred->cr_uid)
132				continue;
133			break;
134		case ACL_USER:
135			if (entry->ae_id != cred->cr_uid)
136				continue;
137			break;
138		case ACL_GROUP_OBJ:
139			if (!groupmember(file_gid, cred))
140				continue;
141			break;
142		case ACL_GROUP:
143			if (!groupmember(entry->ae_id, cred))
144				continue;
145			break;
146		default:
147			KASSERT(entry->ae_tag == ACL_EVERYONE,
148			    ("entry->ae_tag == ACL_EVERYONE"));
149		}
150
151		if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
152			if (entry->ae_perm & access_mask) {
153				if (denied_explicitly != NULL)
154					*denied_explicitly = 1;
155				return (1);
156			}
157		}
158
159		access_mask &= ~(entry->ae_perm);
160		if (access_mask == 0)
161			return (0);
162	}
163
164	return (1);
165}
166
167int
168vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
169    struct acl *aclp, accmode_t accmode, struct ucred *cred, int *privused)
170{
171	accmode_t priv_granted = 0;
172	int denied, explicitly_denied, access_mask, is_directory,
173	    must_be_owner = 0;
174	mode_t file_mode = 0;
175
176	KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND |
177	    VEXPLICIT_DENY | VREAD_NAMED_ATTRS | VWRITE_NAMED_ATTRS |
178	    VDELETE_CHILD | VREAD_ATTRIBUTES | VWRITE_ATTRIBUTES | VDELETE |
179	    VREAD_ACL | VWRITE_ACL | VWRITE_OWNER | VSYNCHRONIZE)) == 0,
180	    ("invalid bit in accmode"));
181	KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
182	    	("VAPPEND without VWRITE"));
183
184	if (privused != NULL)
185		*privused = 0;
186
187	if (accmode & VADMIN)
188		must_be_owner = 1;
189
190	/*
191	 * Ignore VSYNCHRONIZE permission.
192	 */
193	accmode &= ~VSYNCHRONIZE;
194
195	access_mask = _access_mask_from_accmode(accmode);
196
197	if (type == VDIR)
198		is_directory = 1;
199	else
200		is_directory = 0;
201
202	/*
203	 * File owner is always allowed to read and write the ACL
204	 * and basic attributes.  This is to prevent a situation
205	 * where user would change ACL in a way that prevents him
206	 * from undoing the change.
207	 */
208	if (file_uid == cred->cr_uid)
209		access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
210		    ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
211
212	/*
213	 * Ignore append permission for regular files; use write
214	 * permission instead.
215	 */
216	if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
217		access_mask &= ~ACL_APPEND_DATA;
218		access_mask |= ACL_WRITE_DATA;
219	}
220
221	denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
222	    &explicitly_denied);
223
224	if (must_be_owner) {
225		if (file_uid != cred->cr_uid)
226			denied = EPERM;
227	}
228
229	/*
230	 * For VEXEC, ensure that at least one execute bit is set for
231	 * non-directories. We have to check the mode here to stay
232	 * consistent with execve(2). See the test in
233	 * exec_check_permissions().
234	 */
235	acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
236	if (!denied && !is_directory && (accmode & VEXEC) &&
237	    (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
238		denied = EACCES;
239
240	if (!denied)
241		return (0);
242
243	/*
244	 * Access failed.  Iff it was not denied explicitly and
245	 * VEXPLICIT_DENY flag was specified, allow access.
246	 */
247	if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
248		return (0);
249
250	accmode &= ~VEXPLICIT_DENY;
251
252	/*
253	 * No match.  Try to use privileges, if there are any.
254	 */
255	if (is_directory) {
256		if ((accmode & VEXEC) && !priv_check_cred(cred,
257		    PRIV_VFS_LOOKUP, 0))
258			priv_granted |= VEXEC;
259	} else {
260		/*
261		 * Ensure that at least one execute bit is on. Otherwise,
262		 * a privileged user will always succeed, and we don't want
263		 * this to happen unless the file really is executable.
264		 */
265		if ((accmode & VEXEC) && (file_mode &
266		    (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
267		    !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
268			priv_granted |= VEXEC;
269	}
270
271	if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ, 0))
272		priv_granted |= VREAD;
273
274	if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
275	    !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
276		priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
277
278	if ((accmode & VADMIN_PERMS) &&
279	    !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
280		priv_granted |= VADMIN_PERMS;
281
282	if ((accmode & VSTAT_PERMS) &&
283	    !priv_check_cred(cred, PRIV_VFS_STAT, 0))
284		priv_granted |= VSTAT_PERMS;
285
286	if ((accmode & priv_granted) == accmode) {
287		if (privused != NULL)
288			*privused = 1;
289
290		return (0);
291	}
292
293	if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
294		denied = EPERM;
295	else
296		denied = EACCES;
297
298	return (denied);
299}
300#endif /* _KERNEL */
301
302static int
303_acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
304    acl_entry_type_t entry_type)
305{
306	if (entry->ae_tag != tag)
307		return (0);
308
309	if (entry->ae_id != ACL_UNDEFINED_ID)
310		return (0);
311
312	if (entry->ae_perm != perm)
313		return (0);
314
315	if (entry->ae_entry_type != entry_type)
316		return (0);
317
318	if (entry->ae_flags != 0)
319		return (0);
320
321	return (1);
322}
323
324static struct acl_entry *
325_acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
326    acl_entry_type_t entry_type)
327{
328	struct acl_entry *entry;
329
330	KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
331	    ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
332
333	entry = &(aclp->acl_entry[aclp->acl_cnt]);
334	aclp->acl_cnt++;
335
336	entry->ae_tag = tag;
337	entry->ae_id = ACL_UNDEFINED_ID;
338	entry->ae_perm = perm;
339	entry->ae_entry_type = entry_type;
340	entry->ae_flags = 0;
341
342	return (entry);
343}
344
345static struct acl_entry *
346_acl_duplicate_entry(struct acl *aclp, int entry_index)
347{
348	int i;
349
350	KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
351	    ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
352
353	for (i = aclp->acl_cnt; i > entry_index; i--)
354		aclp->acl_entry[i] = aclp->acl_entry[i - 1];
355
356	aclp->acl_cnt++;
357
358	return (&(aclp->acl_entry[entry_index + 1]));
359}
360
361static void
362acl_nfs4_sync_acl_from_mode_draft(struct acl *aclp, mode_t mode,
363    int file_owner_id)
364{
365	int i, meets, must_append;
366	struct acl_entry *entry, *copy, *previous,
367	    *a1, *a2, *a3, *a4, *a5, *a6;
368	mode_t amode;
369	const int READ = 04;
370	const int WRITE = 02;
371	const int EXEC = 01;
372
373	KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
374	    ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
375
376	/*
377	 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
378	 *
379	 * 3.16.6.3. Applying a Mode to an Existing ACL
380	 */
381
382	/*
383	 * 1. For each ACE:
384	 */
385	for (i = 0; i < aclp->acl_cnt; i++) {
386		entry = &(aclp->acl_entry[i]);
387
388		/*
389		 * 1.1. If the type is neither ALLOW or DENY - skip.
390		 */
391		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
392		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
393			continue;
394
395		/*
396		 * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
397		 */
398		if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
399			continue;
400
401		/*
402		 * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
403		 *      are set:
404		 */
405		if (entry->ae_flags &
406		    (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
407			/*
408			 * 1.3.1. A copy of the current ACE is made, and placed
409			 *        in the ACL immediately following the current
410			 *        ACE.
411			 */
412			copy = _acl_duplicate_entry(aclp, i);
413
414			/*
415			 * 1.3.2. In the first ACE, the flag
416			 *        ACL_ENTRY_INHERIT_ONLY is set.
417			 */
418			entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
419
420			/*
421			 * 1.3.3. In the second ACE, the following flags
422			 *        are cleared:
423			 *        ACL_ENTRY_FILE_INHERIT,
424			 *        ACL_ENTRY_DIRECTORY_INHERIT,
425			 *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
426			 */
427			copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
428			    ACL_ENTRY_DIRECTORY_INHERIT |
429			    ACL_ENTRY_NO_PROPAGATE_INHERIT);
430
431			/*
432			 * The algorithm continues on with the second ACE.
433			 */
434			i++;
435			entry = copy;
436		}
437
438		/*
439		 * 1.4. If it's owner@, group@ or everyone@ entry, clear
440		 *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
441		 *      and ACL_EXECUTE.  Continue to the next entry.
442		 */
443		if (entry->ae_tag == ACL_USER_OBJ ||
444		    entry->ae_tag == ACL_GROUP_OBJ ||
445		    entry->ae_tag == ACL_EVERYONE) {
446			entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
447			    ACL_APPEND_DATA | ACL_EXECUTE);
448			continue;
449		}
450
451		/*
452		 * 1.5. Otherwise, if the "who" field did not match one
453		 *      of OWNER@, GROUP@, EVERYONE@:
454		 *
455		 * 1.5.1. If the type is ALLOW, check the preceding ACE.
456		 *        If it does not meet all of the following criteria:
457		 */
458		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
459			continue;
460
461		meets = 0;
462		if (i > 0) {
463			meets = 1;
464			previous = &(aclp->acl_entry[i - 1]);
465
466			/*
467			 * 1.5.1.1. The type field is DENY,
468			 */
469			if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
470				meets = 0;
471
472			/*
473			 * 1.5.1.2. The "who" field is the same as the current
474			 *          ACE,
475			 *
476			 * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
477			 *          is the same as it is in the current ACE,
478			 *          and no other flag bits are set,
479			 */
480			if (previous->ae_id != entry->ae_id ||
481			    previous->ae_tag != entry->ae_tag)
482				meets = 0;
483
484			if (previous->ae_flags)
485				meets = 0;
486
487			/*
488			 * 1.5.1.4. The mask bits are a subset of the mask bits
489			 *          of the current ACE, and are also subset of
490			 *          the following: ACL_READ_DATA,
491			 *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
492			 */
493			if (previous->ae_perm & ~(entry->ae_perm))
494				meets = 0;
495
496			if (previous->ae_perm & ~(ACL_READ_DATA |
497			    ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
498				meets = 0;
499		}
500
501		if (!meets) {
502			/*
503		 	 * Then the ACE of type DENY, with a who equal
504			 * to the current ACE, flag bits equal to
505			 * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
506			 * and no mask bits, is prepended.
507			 */
508			previous = entry;
509			entry = _acl_duplicate_entry(aclp, i);
510
511			/* Adjust counter, as we've just added an entry. */
512			i++;
513
514			previous->ae_tag = entry->ae_tag;
515			previous->ae_id = entry->ae_id;
516			previous->ae_flags = entry->ae_flags;
517			previous->ae_perm = 0;
518			previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
519		}
520
521		/*
522		 * 1.5.2. The following modifications are made to the prepended
523		 *        ACE.  The intent is to mask the following ACE
524		 *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
525		 *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
526		 *        permissions of the new mode.  As a special case,
527		 *        if the ACE matches the current owner of the file,
528		 *        the owner bits are used, rather than the group bits.
529		 *        This is reflected in the algorithm below.
530		 */
531		amode = mode >> 3;
532
533		/*
534		 * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
535		 * in ACE matches the owner of the file, we shift amode three
536		 * more bits, in order to have the owner permission bits
537		 * placed in the three low order bits of amode.
538		 */
539		if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
540			amode = amode >> 3;
541
542		if (entry->ae_perm & ACL_READ_DATA) {
543			if (amode & READ)
544				previous->ae_perm &= ~ACL_READ_DATA;
545			else
546				previous->ae_perm |= ACL_READ_DATA;
547		}
548
549		if (entry->ae_perm & ACL_WRITE_DATA) {
550			if (amode & WRITE)
551				previous->ae_perm &= ~ACL_WRITE_DATA;
552			else
553				previous->ae_perm |= ACL_WRITE_DATA;
554		}
555
556		if (entry->ae_perm & ACL_APPEND_DATA) {
557			if (amode & WRITE)
558				previous->ae_perm &= ~ACL_APPEND_DATA;
559			else
560				previous->ae_perm |= ACL_APPEND_DATA;
561		}
562
563		if (entry->ae_perm & ACL_EXECUTE) {
564			if (amode & EXEC)
565				previous->ae_perm &= ~ACL_EXECUTE;
566			else
567				previous->ae_perm |= ACL_EXECUTE;
568		}
569
570		/*
571		 * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
572		 *        of the ALLOW ace:
573		 *
574		 * XXX: This point is not there in the Falkner's draft.
575		 */
576		if (entry->ae_tag == ACL_GROUP &&
577		    entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
578			mode_t extramode, ownermode;
579			extramode = (mode >> 3) & 07;
580			ownermode = mode >> 6;
581			extramode &= ~ownermode;
582
583			if (extramode) {
584				if (extramode & READ) {
585					entry->ae_perm &= ~ACL_READ_DATA;
586					previous->ae_perm &= ~ACL_READ_DATA;
587				}
588
589				if (extramode & WRITE) {
590					entry->ae_perm &=
591					    ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
592					previous->ae_perm &=
593					    ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
594				}
595
596				if (extramode & EXEC) {
597					entry->ae_perm &= ~ACL_EXECUTE;
598					previous->ae_perm &= ~ACL_EXECUTE;
599				}
600			}
601		}
602	}
603
604	/*
605	 * 2. If there at least six ACEs, the final six ACEs are examined.
606	 *    If they are not equal to what we want, append six ACEs.
607	 */
608	must_append = 0;
609	if (aclp->acl_cnt < 6) {
610		must_append = 1;
611	} else {
612		a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
613		a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
614		a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
615		a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
616		a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
617		a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
618
619		if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
620		    ACL_ENTRY_TYPE_DENY))
621			must_append = 1;
622		if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
623		    ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
624		    ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
625			must_append = 1;
626		if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
627		    ACL_ENTRY_TYPE_DENY))
628			must_append = 1;
629		if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
630		    ACL_ENTRY_TYPE_ALLOW))
631			must_append = 1;
632		if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
633		    ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
634		    ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
635			must_append = 1;
636		if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
637		    ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
638		    ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
639			must_append = 1;
640	}
641
642	if (must_append) {
643		KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
644		    ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
645
646		a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
647		a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
648		    ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
649		    ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
650		a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
651		a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
652		a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
653		    ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
654		    ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
655		a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
656		    ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
657		    ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
658
659		KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
660		    a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
661	}
662
663	/*
664	 * 3. The final six ACEs are adjusted according to the incoming mode.
665	 */
666	if (mode & S_IRUSR)
667		a2->ae_perm |= ACL_READ_DATA;
668	else
669		a1->ae_perm |= ACL_READ_DATA;
670	if (mode & S_IWUSR)
671		a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
672	else
673		a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
674	if (mode & S_IXUSR)
675		a2->ae_perm |= ACL_EXECUTE;
676	else
677		a1->ae_perm |= ACL_EXECUTE;
678
679	if (mode & S_IRGRP)
680		a4->ae_perm |= ACL_READ_DATA;
681	else
682		a3->ae_perm |= ACL_READ_DATA;
683	if (mode & S_IWGRP)
684		a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
685	else
686		a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
687	if (mode & S_IXGRP)
688		a4->ae_perm |= ACL_EXECUTE;
689	else
690		a3->ae_perm |= ACL_EXECUTE;
691
692	if (mode & S_IROTH)
693		a6->ae_perm |= ACL_READ_DATA;
694	else
695		a5->ae_perm |= ACL_READ_DATA;
696	if (mode & S_IWOTH)
697		a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
698	else
699		a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
700	if (mode & S_IXOTH)
701		a6->ae_perm |= ACL_EXECUTE;
702	else
703		a5->ae_perm |= ACL_EXECUTE;
704}
705
706#ifdef _KERNEL
707void
708acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
709    int file_owner_id)
710{
711
712	if (acl_nfs4_old_semantics)
713		acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
714	else
715		acl_nfs4_trivial_from_mode(aclp, mode);
716}
717#endif /* _KERNEL */
718
719void
720acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
721{
722	int i;
723	mode_t old_mode = *_mode, mode = 0, seen = 0;
724	const struct acl_entry *entry;
725
726	KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
727	KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
728	    ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
729
730	/*
731	 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
732	 *
733	 * 3.16.6.1. Recomputing mode upon SETATTR of ACL
734	 */
735
736	for (i = 0; i < aclp->acl_cnt; i++) {
737		entry = &(aclp->acl_entry[i]);
738
739		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
740		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
741			continue;
742
743		if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
744			continue;
745
746		if (entry->ae_tag == ACL_USER_OBJ) {
747			if ((entry->ae_perm & ACL_READ_DATA) &&
748			    ((seen & S_IRUSR) == 0)) {
749				seen |= S_IRUSR;
750				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
751					mode |= S_IRUSR;
752			}
753			if ((entry->ae_perm & ACL_WRITE_DATA) &&
754			     ((seen & S_IWUSR) == 0)) {
755				seen |= S_IWUSR;
756				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
757					mode |= S_IWUSR;
758			}
759			if ((entry->ae_perm & ACL_EXECUTE) &&
760			    ((seen & S_IXUSR) == 0)) {
761				seen |= S_IXUSR;
762				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
763					mode |= S_IXUSR;
764			}
765		} else if (entry->ae_tag == ACL_GROUP_OBJ) {
766			if ((entry->ae_perm & ACL_READ_DATA) &&
767			    ((seen & S_IRGRP) == 0)) {
768				seen |= S_IRGRP;
769				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
770					mode |= S_IRGRP;
771			}
772			if ((entry->ae_perm & ACL_WRITE_DATA) &&
773			    ((seen & S_IWGRP) == 0)) {
774				seen |= S_IWGRP;
775				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
776					mode |= S_IWGRP;
777			}
778			if ((entry->ae_perm & ACL_EXECUTE) &&
779			    ((seen & S_IXGRP) == 0)) {
780				seen |= S_IXGRP;
781				if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
782					mode |= S_IXGRP;
783			}
784		} else if (entry->ae_tag == ACL_EVERYONE) {
785			if (entry->ae_perm & ACL_READ_DATA) {
786				if ((seen & S_IRUSR) == 0) {
787					seen |= S_IRUSR;
788					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
789						mode |= S_IRUSR;
790				}
791				if ((seen & S_IRGRP) == 0) {
792					seen |= S_IRGRP;
793					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
794						mode |= S_IRGRP;
795				}
796				if ((seen & S_IROTH) == 0) {
797					seen |= S_IROTH;
798					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
799						mode |= S_IROTH;
800				}
801			}
802			if (entry->ae_perm & ACL_WRITE_DATA) {
803				if ((seen & S_IWUSR) == 0) {
804					seen |= S_IWUSR;
805					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
806						mode |= S_IWUSR;
807				}
808				if ((seen & S_IWGRP) == 0) {
809					seen |= S_IWGRP;
810					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
811						mode |= S_IWGRP;
812				}
813				if ((seen & S_IWOTH) == 0) {
814					seen |= S_IWOTH;
815					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
816						mode |= S_IWOTH;
817				}
818			}
819			if (entry->ae_perm & ACL_EXECUTE) {
820				if ((seen & S_IXUSR) == 0) {
821					seen |= S_IXUSR;
822					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
823						mode |= S_IXUSR;
824				}
825				if ((seen & S_IXGRP) == 0) {
826					seen |= S_IXGRP;
827					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
828						mode |= S_IXGRP;
829				}
830				if ((seen & S_IXOTH) == 0) {
831					seen |= S_IXOTH;
832					if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
833						mode |= S_IXOTH;
834				}
835			}
836		}
837	}
838
839	*_mode = mode | (old_mode & ACL_PRESERVE_MASK);
840}
841
842#ifdef _KERNEL
843/*
844 * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
845 * draft-ietf-nfsv4-minorversion1-03.txt.
846 */
847static void
848acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
849    struct acl *child_aclp, mode_t mode, int file_owner_id,
850    int is_directory)
851{
852	int i, flags;
853	const struct acl_entry *parent_entry;
854	struct acl_entry *entry, *copy;
855
856	KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
857	KASSERT(parent_aclp->acl_cnt > 0, ("parent_aclp->acl_cnt > 0"));
858	KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
859	    ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
860
861	/*
862	 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
863	 *
864	 * 3.16.6.2. Applying the mode given to CREATE or OPEN
865	 *           to an inherited ACL
866	 */
867
868	/*
869	 * 1. Form an ACL that is the concatenation of all inheritable ACEs.
870	 */
871	for (i = 0; i < parent_aclp->acl_cnt; i++) {
872		parent_entry = &(parent_aclp->acl_entry[i]);
873		flags = parent_entry->ae_flags;
874
875		/*
876		 * Entry is not inheritable at all.
877		 */
878		if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
879		    ACL_ENTRY_FILE_INHERIT)) == 0)
880			continue;
881
882		/*
883		 * We're creating a file, but entry is not inheritable
884		 * by files.
885		 */
886		if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
887			continue;
888
889		/*
890		 * Entry is inheritable only by files, but has NO_PROPAGATE
891		 * flag set, and we're creating a directory, so it wouldn't
892		 * propagate to any file in that directory anyway.
893		 */
894		if (is_directory &&
895		    (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
896		    (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
897			continue;
898
899		KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
900		    ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
901		child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
902		child_aclp->acl_cnt++;
903	}
904
905	/*
906	 * 2. For each entry in the new ACL, adjust its flags, possibly
907	 *    creating two entries in place of one.
908	 */
909	for (i = 0; i < child_aclp->acl_cnt; i++) {
910		entry = &(child_aclp->acl_entry[i]);
911
912		/*
913		 * This is not in the specification, but SunOS
914		 * apparently does that.
915		 */
916		if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
917		    !is_directory) &&
918		    entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
919			entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
920
921		/*
922		 * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
923		 *      being created is not a directory, then clear the
924		 *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
925		 *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
926		 *      ACL_ENTRY_INHERIT_ONLY.
927		 */
928		if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
929		    !is_directory) {
930			entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
931			ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
932			ACL_ENTRY_INHERIT_ONLY);
933
934			/*
935			 * Continue on to the next ACE.
936			 */
937			continue;
938		}
939
940		/*
941		 * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
942		 *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
943		 *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
944		 *      next ACE.  Otherwise...
945		 */
946		/*
947		 * XXX: Read it again and make sure what does the "otherwise"
948		 *      apply to.
949		 */
950		if (is_directory &&
951		    (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
952		    ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
953			entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
954			continue;
955		}
956
957		/*
958		 * 2.C. If the type of the ACE is neither ALLOW nor deny,
959		 *      then continue.
960		 */
961		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
962		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
963			continue;
964
965		/*
966		 * 2.D. Copy the original ACE into a second, adjacent ACE.
967		 */
968		copy = _acl_duplicate_entry(child_aclp, i);
969
970		/*
971		 * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
972		 *      is set.
973		 */
974		entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
975
976		/*
977		 * 2.F. On the second ACE, clear the following flags:
978		 *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
979		 *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
980		 */
981		copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
982		    ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
983		    ACL_ENTRY_INHERIT_ONLY);
984
985		/*
986		 * 2.G. On the second ACE, if the type is ALLOW,
987		 *      an implementation MAY clear the following
988		 *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
989		 */
990		if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
991			copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
992
993		/*
994		 * Increment the counter to skip the copied entry.
995		 */
996		i++;
997	}
998
999	/*
1000	 * 3. To ensure that the mode is honored, apply the algorithm describe
1001	 *    in Section 2.16.6.3, using the mode that is to be used for file
1002	 *    creation.
1003	 */
1004	acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1005}
1006#endif /* _KERNEL */
1007
1008/*
1009 * Populate the ACL with entries inherited from parent_aclp.
1010 */
1011static void
1012acl_nfs4_inherit_entries(const struct acl *parent_aclp,
1013    struct acl *child_aclp, mode_t mode, int file_owner_id,
1014    int is_directory)
1015{
1016	int i, flags, tag;
1017	const struct acl_entry *parent_entry;
1018	struct acl_entry *entry;
1019
1020	KASSERT(parent_aclp->acl_cnt > 0, ("parent_aclp->acl_cnt > 0"));
1021	KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
1022	    ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
1023
1024	for (i = 0; i < parent_aclp->acl_cnt; i++) {
1025		parent_entry = &(parent_aclp->acl_entry[i]);
1026		flags = parent_entry->ae_flags;
1027		tag = parent_entry->ae_tag;
1028
1029		/*
1030		 * Don't inherit owner@, group@, or everyone@ entries.
1031		 */
1032		if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
1033		    tag == ACL_EVERYONE)
1034			continue;
1035
1036		/*
1037		 * Entry is not inheritable at all.
1038		 */
1039		if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
1040		    ACL_ENTRY_FILE_INHERIT)) == 0)
1041			continue;
1042
1043		/*
1044		 * We're creating a file, but entry is not inheritable
1045		 * by files.
1046		 */
1047		if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
1048			continue;
1049
1050		/*
1051		 * Entry is inheritable only by files, but has NO_PROPAGATE
1052		 * flag set, and we're creating a directory, so it wouldn't
1053		 * propagate to any file in that directory anyway.
1054		 */
1055		if (is_directory &&
1056		    (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
1057		    (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
1058			continue;
1059
1060		/*
1061		 * Entry qualifies for being inherited.
1062		 */
1063		KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
1064		    ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
1065		entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
1066		*entry = *parent_entry;
1067		child_aclp->acl_cnt++;
1068
1069		entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
1070
1071		/*
1072		 * If the type of the ACE is neither ALLOW nor DENY,
1073		 * then leave it as it is and proceed to the next one.
1074		 */
1075		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1076		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1077			continue;
1078
1079		/*
1080		 * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
1081		 * the object being created is not a directory, then clear
1082		 * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
1083		 * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
1084		 * ACL_ENTRY_INHERIT_ONLY.
1085		 */
1086		if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
1087		    !is_directory) {
1088			entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
1089			ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
1090			ACL_ENTRY_INHERIT_ONLY);
1091		}
1092
1093		/*
1094		 * If the object is a directory and ACL_ENTRY_FILE_INHERIT
1095		 * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
1096		 * that ACL_ENTRY_INHERIT_ONLY is set.
1097		 */
1098		if (is_directory &&
1099		    (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
1100		    ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
1101			entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
1102		}
1103
1104		if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
1105		    (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
1106			/*
1107			 * Some permissions must never be inherited.
1108			 */
1109			entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
1110			    ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
1111
1112			/*
1113			 * Others must be masked according to the file mode.
1114			 */
1115			if ((mode & S_IRGRP) == 0)
1116				entry->ae_perm &= ~ACL_READ_DATA;
1117			if ((mode & S_IWGRP) == 0)
1118				entry->ae_perm &=
1119				    ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
1120			if ((mode & S_IXGRP) == 0)
1121				entry->ae_perm &= ~ACL_EXECUTE;
1122		}
1123	}
1124}
1125
1126/*
1127 * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
1128 * It's also being used to calculate a trivial ACL, by inheriting from
1129 * a NULL ACL.
1130 */
1131static void
1132acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
1133    struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
1134{
1135	acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
1136	acl_perm_t user_allow, group_allow, everyone_allow;
1137
1138	KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
1139
1140	user_allow = group_allow = everyone_allow = ACL_READ_ACL |
1141	    ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
1142	user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
1143	    ACL_WRITE_NAMED_ATTRS;
1144
1145	if (mode & S_IRUSR)
1146		user_allow |= ACL_READ_DATA;
1147	if (mode & S_IWUSR)
1148		user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1149	if (mode & S_IXUSR)
1150		user_allow |= ACL_EXECUTE;
1151
1152	if (mode & S_IRGRP)
1153		group_allow |= ACL_READ_DATA;
1154	if (mode & S_IWGRP)
1155		group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1156	if (mode & S_IXGRP)
1157		group_allow |= ACL_EXECUTE;
1158
1159	if (mode & S_IROTH)
1160		everyone_allow |= ACL_READ_DATA;
1161	if (mode & S_IWOTH)
1162		everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1163	if (mode & S_IXOTH)
1164		everyone_allow |= ACL_EXECUTE;
1165
1166	user_deny = ((group_allow | everyone_allow) & ~user_allow);
1167	group_deny = everyone_allow & ~group_allow;
1168	user_allow_first = group_deny & ~user_deny;
1169
1170	if (user_allow_first != 0)
1171		_acl_append(aclp, ACL_USER_OBJ, user_allow_first,
1172		    ACL_ENTRY_TYPE_ALLOW);
1173	if (user_deny != 0)
1174		_acl_append(aclp, ACL_USER_OBJ, user_deny,
1175		    ACL_ENTRY_TYPE_DENY);
1176	if (group_deny != 0)
1177		_acl_append(aclp, ACL_GROUP_OBJ, group_deny,
1178		    ACL_ENTRY_TYPE_DENY);
1179
1180	if (parent_aclp != NULL)
1181		acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
1182		    file_owner_id, is_directory);
1183
1184	_acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
1185	_acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
1186	_acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
1187}
1188
1189#ifdef _KERNEL
1190void
1191acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
1192    struct acl *child_aclp, mode_t mode, int file_owner_id,
1193    int is_directory)
1194{
1195
1196	if (acl_nfs4_old_semantics)
1197		acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
1198		    mode, file_owner_id, is_directory);
1199	else
1200		acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
1201		    mode, file_owner_id, is_directory);
1202}
1203#endif /* _KERNEL */
1204
1205/*
1206 * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
1207 * Note that this results in an ACL different from (but semantically
1208 * equal to) the "canonical six" trivial ACL computed using algorithm
1209 * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
1210 */
1211static void
1212acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
1213{
1214
1215	aclp->acl_cnt = 0;
1216	acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
1217}
1218
1219#ifndef _KERNEL
1220/*
1221 * This routine is used by libc to implement acl_strip_np(3)
1222 * and acl_is_trivial_np(3).
1223 */
1224void
1225acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
1226{
1227
1228	aclp->acl_cnt = 0;
1229	if (canonical_six)
1230		acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
1231	else
1232		acl_nfs4_trivial_from_mode(aclp, mode);
1233}
1234#endif /* !_KERNEL */
1235
1236#ifdef _KERNEL
1237static int
1238_acls_are_equal(const struct acl *a, const struct acl *b)
1239{
1240	int i;
1241	const struct acl_entry *entrya, *entryb;
1242
1243	if (a->acl_cnt != b->acl_cnt)
1244		return (0);
1245
1246	for (i = 0; i < b->acl_cnt; i++) {
1247		entrya = &(a->acl_entry[i]);
1248		entryb = &(b->acl_entry[i]);
1249
1250		if (entrya->ae_tag != entryb->ae_tag ||
1251		    entrya->ae_id != entryb->ae_id ||
1252		    entrya->ae_perm != entryb->ae_perm ||
1253		    entrya->ae_entry_type != entryb->ae_entry_type ||
1254		    entrya->ae_flags != entryb->ae_flags)
1255			return (0);
1256	}
1257
1258	return (1);
1259}
1260
1261/*
1262 * This routine is used to determine whether to remove extended attribute
1263 * that stores ACL contents.
1264 */
1265int
1266acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1267{
1268	int trivial;
1269	mode_t tmpmode = 0;
1270	struct acl *tmpaclp;
1271
1272	if (aclp->acl_cnt > 6)
1273		return (0);
1274
1275	/*
1276	 * Compute the mode from the ACL, then compute new ACL from that mode.
1277	 * If the ACLs are identical, then the ACL is trivial.
1278	 *
1279	 * XXX: I guess there is a faster way to do this.  However, even
1280	 *      this slow implementation significantly speeds things up
1281	 *      for files that don't have non-trivial ACLs - it's critical
1282	 *      for performance to not use EA when they are not needed.
1283	 *
1284	 * First try the PSARC/2010/029 semantics.
1285	 */
1286	tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1287	acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1288	acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
1289	trivial = _acls_are_equal(aclp, tmpaclp);
1290	if (trivial) {
1291		acl_free(tmpaclp);
1292		return (trivial);
1293	}
1294
1295	/*
1296	 * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
1297	 */
1298	tmpaclp->acl_cnt = 0;
1299	acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
1300	trivial = _acls_are_equal(aclp, tmpaclp);
1301	acl_free(tmpaclp);
1302
1303	return (trivial);
1304}
1305#endif /* _KERNEL */
1306
1307int
1308acl_nfs4_check(const struct acl *aclp, int is_directory)
1309{
1310	int i;
1311	const struct acl_entry *entry;
1312
1313	/*
1314	 * The spec doesn't seem to say anything about ACL validity.
1315	 * It seems there is not much to do here.  There is even no need
1316	 * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1317	 * entries, as there can be several of them and that's perfectly
1318	 * valid.  There can be none of them too.  Really.
1319	 */
1320
1321	if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1322		return (EINVAL);
1323
1324	for (i = 0; i < aclp->acl_cnt; i++) {
1325		entry = &(aclp->acl_entry[i]);
1326
1327		switch (entry->ae_tag) {
1328		case ACL_USER_OBJ:
1329		case ACL_GROUP_OBJ:
1330		case ACL_EVERYONE:
1331			if (entry->ae_id != ACL_UNDEFINED_ID)
1332				return (EINVAL);
1333			break;
1334
1335		case ACL_USER:
1336		case ACL_GROUP:
1337			if (entry->ae_id == ACL_UNDEFINED_ID)
1338				return (EINVAL);
1339			break;
1340
1341		default:
1342			return (EINVAL);
1343		}
1344
1345		if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1346			return (EINVAL);
1347
1348		/*
1349		 * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1350		 */
1351		if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1352		    entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1353			return (EINVAL);
1354
1355		if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1356			return (EINVAL);
1357
1358		/* Disallow unimplemented flags. */
1359		if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1360		    ACL_ENTRY_FAILED_ACCESS))
1361			return (EINVAL);
1362
1363		/* Disallow flags not allowed for ordinary files. */
1364		if (!is_directory) {
1365			if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1366			    ACL_ENTRY_DIRECTORY_INHERIT |
1367			    ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1368				return (EINVAL);
1369		}
1370	}
1371
1372	return (0);
1373}
1374