1/*
2 *  Common NFSv4 ACL handling code.
3 *
4 *  Copyright (c) 2002, 2003 The Regents of the University of Michigan.
5 *  All rights reserved.
6 *
7 *  Marius Aamodt Eriksen <marius@umich.edu>
8 *  Jeff Sedlak <jsedlak@umich.edu>
9 *  J. Bruce Fields <bfields@umich.edu>
10 *
11 *  Redistribution and use in source and binary forms, with or without
12 *  modification, are permitted provided that the following conditions
13 *  are met:
14 *
15 *  1. Redistributions of source code must retain the above copyright
16 *     notice, this list of conditions and the following disclaimer.
17 *  2. Redistributions in binary form must reproduce the above copyright
18 *     notice, this list of conditions and the following disclaimer in the
19 *     documentation and/or other materials provided with the distribution.
20 *  3. Neither the name of the University nor the names of its
21 *     contributors may be used to endorse or promote products derived
22 *     from this software without specific prior written permission.
23 *
24 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <linux/slab.h>
38#include <linux/nfs_fs.h>
39#include "nfsfh.h"
40#include "nfsd.h"
41#include "acl.h"
42#include "vfs.h"
43
44#define NFS4_ACL_TYPE_DEFAULT	0x01
45#define NFS4_ACL_DIR		0x02
46#define NFS4_ACL_OWNER		0x04
47
48/* mode bit translations: */
49#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
50#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
51#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
52#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
53#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
54
55/* We don't support these bits; insist they be neither allowed nor denied */
56#define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
57		| NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
58
59/* flags used to simulate posix default ACLs */
60#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
61		| NFS4_ACE_DIRECTORY_INHERIT_ACE)
62
63#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
64		| NFS4_ACE_INHERIT_ONLY_ACE \
65		| NFS4_ACE_IDENTIFIER_GROUP)
66
67#define MASK_EQUAL(mask1, mask2) \
68	( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
69
70static u32
71mask_from_posix(unsigned short perm, unsigned int flags)
72{
73	int mask = NFS4_ANYONE_MODE;
74
75	if (flags & NFS4_ACL_OWNER)
76		mask |= NFS4_OWNER_MODE;
77	if (perm & ACL_READ)
78		mask |= NFS4_READ_MODE;
79	if (perm & ACL_WRITE)
80		mask |= NFS4_WRITE_MODE;
81	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
82		mask |= NFS4_ACE_DELETE_CHILD;
83	if (perm & ACL_EXECUTE)
84		mask |= NFS4_EXECUTE_MODE;
85	return mask;
86}
87
88static u32
89deny_mask_from_posix(unsigned short perm, u32 flags)
90{
91	u32 mask = 0;
92
93	if (perm & ACL_READ)
94		mask |= NFS4_READ_MODE;
95	if (perm & ACL_WRITE)
96		mask |= NFS4_WRITE_MODE;
97	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
98		mask |= NFS4_ACE_DELETE_CHILD;
99	if (perm & ACL_EXECUTE)
100		mask |= NFS4_EXECUTE_MODE;
101	return mask;
102}
103
104/* XXX: modify functions to return NFS errors; they're only ever
105 * used by nfs code, after all.... */
106
107/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
108 * side of being more restrictive, so the mode bit mapping below is
109 * pessimistic.  An optimistic version would be needed to handle DENY's,
110 * but we espect to coalesce all ALLOWs and DENYs before mapping to mode
111 * bits. */
112
113static void
114low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
115{
116	u32 write_mode = NFS4_WRITE_MODE;
117
118	if (flags & NFS4_ACL_DIR)
119		write_mode |= NFS4_ACE_DELETE_CHILD;
120	*mode = 0;
121	if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
122		*mode |= ACL_READ;
123	if ((perm & write_mode) == write_mode)
124		*mode |= ACL_WRITE;
125	if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
126		*mode |= ACL_EXECUTE;
127}
128
129struct ace_container {
130	struct nfs4_ace  *ace;
131	struct list_head  ace_l;
132};
133
134static short ace2type(struct nfs4_ace *);
135static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
136				unsigned int);
137
138int
139nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
140		struct nfs4_acl **acl)
141{
142	struct inode *inode = d_inode(dentry);
143	int error = 0;
144	struct posix_acl *pacl = NULL, *dpacl = NULL;
145	unsigned int flags = 0;
146	int size = 0;
147
148	pacl = get_acl(inode, ACL_TYPE_ACCESS);
149	if (!pacl)
150		pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
151
152	if (IS_ERR(pacl))
153		return PTR_ERR(pacl);
154
155	/* allocate for worst case: one (deny, allow) pair each: */
156	size += 2 * pacl->a_count;
157
158	if (S_ISDIR(inode->i_mode)) {
159		flags = NFS4_ACL_DIR;
160		dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
161		if (IS_ERR(dpacl)) {
162			error = PTR_ERR(dpacl);
163			goto rel_pacl;
164		}
165
166		if (dpacl)
167			size += 2 * dpacl->a_count;
168	}
169
170	*acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
171	if (*acl == NULL) {
172		error = -ENOMEM;
173		goto out;
174	}
175	(*acl)->naces = 0;
176
177	_posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
178
179	if (dpacl)
180		_posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
181
182out:
183	posix_acl_release(dpacl);
184rel_pacl:
185	posix_acl_release(pacl);
186	return error;
187}
188
189struct posix_acl_summary {
190	unsigned short owner;
191	unsigned short users;
192	unsigned short group;
193	unsigned short groups;
194	unsigned short other;
195	unsigned short mask;
196};
197
198static void
199summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
200{
201	struct posix_acl_entry *pa, *pe;
202
203	/*
204	 * Only pas.users and pas.groups need initialization; previous
205	 * posix_acl_valid() calls ensure that the other fields will be
206	 * initialized in the following loop.  But, just to placate gcc:
207	 */
208	memset(pas, 0, sizeof(*pas));
209	pas->mask = 07;
210
211	pe = acl->a_entries + acl->a_count;
212
213	FOREACH_ACL_ENTRY(pa, acl, pe) {
214		switch (pa->e_tag) {
215			case ACL_USER_OBJ:
216				pas->owner = pa->e_perm;
217				break;
218			case ACL_GROUP_OBJ:
219				pas->group = pa->e_perm;
220				break;
221			case ACL_USER:
222				pas->users |= pa->e_perm;
223				break;
224			case ACL_GROUP:
225				pas->groups |= pa->e_perm;
226				break;
227			case ACL_OTHER:
228				pas->other = pa->e_perm;
229				break;
230			case ACL_MASK:
231				pas->mask = pa->e_perm;
232				break;
233		}
234	}
235	/* We'll only care about effective permissions: */
236	pas->users &= pas->mask;
237	pas->group &= pas->mask;
238	pas->groups &= pas->mask;
239}
240
241/* We assume the acl has been verified with posix_acl_valid. */
242static void
243_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
244						unsigned int flags)
245{
246	struct posix_acl_entry *pa, *group_owner_entry;
247	struct nfs4_ace *ace;
248	struct posix_acl_summary pas;
249	unsigned short deny;
250	int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
251		NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
252
253	BUG_ON(pacl->a_count < 3);
254	summarize_posix_acl(pacl, &pas);
255
256	pa = pacl->a_entries;
257	ace = acl->aces + acl->naces;
258
259	/* We could deny everything not granted by the owner: */
260	deny = ~pas.owner;
261	/*
262	 * but it is equivalent (and simpler) to deny only what is not
263	 * granted by later entries:
264	 */
265	deny &= pas.users | pas.group | pas.groups | pas.other;
266	if (deny) {
267		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
268		ace->flag = eflag;
269		ace->access_mask = deny_mask_from_posix(deny, flags);
270		ace->whotype = NFS4_ACL_WHO_OWNER;
271		ace++;
272		acl->naces++;
273	}
274
275	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
276	ace->flag = eflag;
277	ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
278	ace->whotype = NFS4_ACL_WHO_OWNER;
279	ace++;
280	acl->naces++;
281	pa++;
282
283	while (pa->e_tag == ACL_USER) {
284		deny = ~(pa->e_perm & pas.mask);
285		deny &= pas.groups | pas.group | pas.other;
286		if (deny) {
287			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
288			ace->flag = eflag;
289			ace->access_mask = deny_mask_from_posix(deny, flags);
290			ace->whotype = NFS4_ACL_WHO_NAMED;
291			ace->who_uid = pa->e_uid;
292			ace++;
293			acl->naces++;
294		}
295		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
296		ace->flag = eflag;
297		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
298						   flags);
299		ace->whotype = NFS4_ACL_WHO_NAMED;
300		ace->who_uid = pa->e_uid;
301		ace++;
302		acl->naces++;
303		pa++;
304	}
305
306	/* In the case of groups, we apply allow ACEs first, then deny ACEs,
307	 * since a user can be in more than one group.  */
308
309	/* allow ACEs */
310
311	group_owner_entry = pa;
312
313	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
314	ace->flag = eflag;
315	ace->access_mask = mask_from_posix(pas.group, flags);
316	ace->whotype = NFS4_ACL_WHO_GROUP;
317	ace++;
318	acl->naces++;
319	pa++;
320
321	while (pa->e_tag == ACL_GROUP) {
322		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
323		ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
324		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
325						   flags);
326		ace->whotype = NFS4_ACL_WHO_NAMED;
327		ace->who_gid = pa->e_gid;
328		ace++;
329		acl->naces++;
330		pa++;
331	}
332
333	/* deny ACEs */
334
335	pa = group_owner_entry;
336
337	deny = ~pas.group & pas.other;
338	if (deny) {
339		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
340		ace->flag = eflag;
341		ace->access_mask = deny_mask_from_posix(deny, flags);
342		ace->whotype = NFS4_ACL_WHO_GROUP;
343		ace++;
344		acl->naces++;
345	}
346	pa++;
347
348	while (pa->e_tag == ACL_GROUP) {
349		deny = ~(pa->e_perm & pas.mask);
350		deny &= pas.other;
351		if (deny) {
352			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
353			ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
354			ace->access_mask = deny_mask_from_posix(deny, flags);
355			ace->whotype = NFS4_ACL_WHO_NAMED;
356			ace->who_gid = pa->e_gid;
357			ace++;
358			acl->naces++;
359		}
360		pa++;
361	}
362
363	if (pa->e_tag == ACL_MASK)
364		pa++;
365	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
366	ace->flag = eflag;
367	ace->access_mask = mask_from_posix(pa->e_perm, flags);
368	ace->whotype = NFS4_ACL_WHO_EVERYONE;
369	acl->naces++;
370}
371
372static bool
373pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
374{
375	if (pace1->e_tag != pace2->e_tag)
376		return pace1->e_tag > pace2->e_tag;
377	if (pace1->e_tag == ACL_USER)
378		return uid_gt(pace1->e_uid, pace2->e_uid);
379	if (pace1->e_tag == ACL_GROUP)
380		return gid_gt(pace1->e_gid, pace2->e_gid);
381	return false;
382}
383
384static void
385sort_pacl_range(struct posix_acl *pacl, int start, int end) {
386	int sorted = 0, i;
387	struct posix_acl_entry tmp;
388
389	/* We just do a bubble sort; easy to do in place, and we're not
390	 * expecting acl's to be long enough to justify anything more. */
391	while (!sorted) {
392		sorted = 1;
393		for (i = start; i < end; i++) {
394			if (pace_gt(&pacl->a_entries[i],
395				    &pacl->a_entries[i+1])) {
396				sorted = 0;
397				tmp = pacl->a_entries[i];
398				pacl->a_entries[i] = pacl->a_entries[i+1];
399				pacl->a_entries[i+1] = tmp;
400			}
401		}
402	}
403}
404
405static void
406sort_pacl(struct posix_acl *pacl)
407{
408	/* posix_acl_valid requires that users and groups be in order
409	 * by uid/gid. */
410	int i, j;
411
412	/* no users or groups */
413	if (!pacl || pacl->a_count <= 4)
414		return;
415
416	i = 1;
417	while (pacl->a_entries[i].e_tag == ACL_USER)
418		i++;
419	sort_pacl_range(pacl, 1, i-1);
420
421	BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
422	j = ++i;
423	while (pacl->a_entries[j].e_tag == ACL_GROUP)
424		j++;
425	sort_pacl_range(pacl, i, j-1);
426	return;
427}
428
429/*
430 * While processing the NFSv4 ACE, this maintains bitmasks representing
431 * which permission bits have been allowed and which denied to a given
432 * entity: */
433struct posix_ace_state {
434	u32 allow;
435	u32 deny;
436};
437
438struct posix_user_ace_state {
439	union {
440		kuid_t uid;
441		kgid_t gid;
442	};
443	struct posix_ace_state perms;
444};
445
446struct posix_ace_state_array {
447	int n;
448	struct posix_user_ace_state aces[];
449};
450
451/*
452 * While processing the NFSv4 ACE, this maintains the partial permissions
453 * calculated so far: */
454
455struct posix_acl_state {
456	int empty;
457	struct posix_ace_state owner;
458	struct posix_ace_state group;
459	struct posix_ace_state other;
460	struct posix_ace_state everyone;
461	struct posix_ace_state mask; /* Deny unused in this case */
462	struct posix_ace_state_array *users;
463	struct posix_ace_state_array *groups;
464};
465
466static int
467init_state(struct posix_acl_state *state, int cnt)
468{
469	int alloc;
470
471	memset(state, 0, sizeof(struct posix_acl_state));
472	state->empty = 1;
473	/*
474	 * In the worst case, each individual acl could be for a distinct
475	 * named user or group, but we don't no which, so we allocate
476	 * enough space for either:
477	 */
478	alloc = sizeof(struct posix_ace_state_array)
479		+ cnt*sizeof(struct posix_user_ace_state);
480	state->users = kzalloc(alloc, GFP_KERNEL);
481	if (!state->users)
482		return -ENOMEM;
483	state->groups = kzalloc(alloc, GFP_KERNEL);
484	if (!state->groups) {
485		kfree(state->users);
486		return -ENOMEM;
487	}
488	return 0;
489}
490
491static void
492free_state(struct posix_acl_state *state) {
493	kfree(state->users);
494	kfree(state->groups);
495}
496
497static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
498{
499	state->mask.allow |= astate->allow;
500}
501
502static struct posix_acl *
503posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
504{
505	struct posix_acl_entry *pace;
506	struct posix_acl *pacl;
507	int nace;
508	int i;
509
510	/*
511	 * ACLs with no ACEs are treated differently in the inheritable
512	 * and effective cases: when there are no inheritable ACEs,
513	 * calls ->set_acl with a NULL ACL structure.
514	 */
515	if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
516		return NULL;
517
518	/*
519	 * When there are no effective ACEs, the following will end
520	 * up setting a 3-element effective posix ACL with all
521	 * permissions zero.
522	 */
523	if (!state->users->n && !state->groups->n)
524		nace = 3;
525	else /* Note we also include a MASK ACE in this case: */
526		nace = 4 + state->users->n + state->groups->n;
527	pacl = posix_acl_alloc(nace, GFP_KERNEL);
528	if (!pacl)
529		return ERR_PTR(-ENOMEM);
530
531	pace = pacl->a_entries;
532	pace->e_tag = ACL_USER_OBJ;
533	low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
534
535	for (i=0; i < state->users->n; i++) {
536		pace++;
537		pace->e_tag = ACL_USER;
538		low_mode_from_nfs4(state->users->aces[i].perms.allow,
539					&pace->e_perm, flags);
540		pace->e_uid = state->users->aces[i].uid;
541		add_to_mask(state, &state->users->aces[i].perms);
542	}
543
544	pace++;
545	pace->e_tag = ACL_GROUP_OBJ;
546	low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
547	add_to_mask(state, &state->group);
548
549	for (i=0; i < state->groups->n; i++) {
550		pace++;
551		pace->e_tag = ACL_GROUP;
552		low_mode_from_nfs4(state->groups->aces[i].perms.allow,
553					&pace->e_perm, flags);
554		pace->e_gid = state->groups->aces[i].gid;
555		add_to_mask(state, &state->groups->aces[i].perms);
556	}
557
558	if (state->users->n || state->groups->n) {
559		pace++;
560		pace->e_tag = ACL_MASK;
561		low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
562	}
563
564	pace++;
565	pace->e_tag = ACL_OTHER;
566	low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
567
568	return pacl;
569}
570
571static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
572{
573	/* Allow all bits in the mask not already denied: */
574	astate->allow |= mask & ~astate->deny;
575}
576
577static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
578{
579	/* Deny all bits in the mask not already allowed: */
580	astate->deny |= mask & ~astate->allow;
581}
582
583static int find_uid(struct posix_acl_state *state, kuid_t uid)
584{
585	struct posix_ace_state_array *a = state->users;
586	int i;
587
588	for (i = 0; i < a->n; i++)
589		if (uid_eq(a->aces[i].uid, uid))
590			return i;
591	/* Not found: */
592	a->n++;
593	a->aces[i].uid = uid;
594	a->aces[i].perms.allow = state->everyone.allow;
595	a->aces[i].perms.deny  = state->everyone.deny;
596
597	return i;
598}
599
600static int find_gid(struct posix_acl_state *state, kgid_t gid)
601{
602	struct posix_ace_state_array *a = state->groups;
603	int i;
604
605	for (i = 0; i < a->n; i++)
606		if (gid_eq(a->aces[i].gid, gid))
607			return i;
608	/* Not found: */
609	a->n++;
610	a->aces[i].gid = gid;
611	a->aces[i].perms.allow = state->everyone.allow;
612	a->aces[i].perms.deny  = state->everyone.deny;
613
614	return i;
615}
616
617static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
618{
619	int i;
620
621	for (i=0; i < a->n; i++)
622		deny_bits(&a->aces[i].perms, mask);
623}
624
625static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
626{
627	int i;
628
629	for (i=0; i < a->n; i++)
630		allow_bits(&a->aces[i].perms, mask);
631}
632
633static void process_one_v4_ace(struct posix_acl_state *state,
634				struct nfs4_ace *ace)
635{
636	u32 mask = ace->access_mask;
637	int i;
638
639	state->empty = 0;
640
641	switch (ace2type(ace)) {
642	case ACL_USER_OBJ:
643		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
644			allow_bits(&state->owner, mask);
645		} else {
646			deny_bits(&state->owner, mask);
647		}
648		break;
649	case ACL_USER:
650		i = find_uid(state, ace->who_uid);
651		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
652			allow_bits(&state->users->aces[i].perms, mask);
653		} else {
654			deny_bits(&state->users->aces[i].perms, mask);
655			mask = state->users->aces[i].perms.deny;
656			deny_bits(&state->owner, mask);
657		}
658		break;
659	case ACL_GROUP_OBJ:
660		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
661			allow_bits(&state->group, mask);
662		} else {
663			deny_bits(&state->group, mask);
664			mask = state->group.deny;
665			deny_bits(&state->owner, mask);
666			deny_bits(&state->everyone, mask);
667			deny_bits_array(state->users, mask);
668			deny_bits_array(state->groups, mask);
669		}
670		break;
671	case ACL_GROUP:
672		i = find_gid(state, ace->who_gid);
673		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
674			allow_bits(&state->groups->aces[i].perms, mask);
675		} else {
676			deny_bits(&state->groups->aces[i].perms, mask);
677			mask = state->groups->aces[i].perms.deny;
678			deny_bits(&state->owner, mask);
679			deny_bits(&state->group, mask);
680			deny_bits(&state->everyone, mask);
681			deny_bits_array(state->users, mask);
682			deny_bits_array(state->groups, mask);
683		}
684		break;
685	case ACL_OTHER:
686		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
687			allow_bits(&state->owner, mask);
688			allow_bits(&state->group, mask);
689			allow_bits(&state->other, mask);
690			allow_bits(&state->everyone, mask);
691			allow_bits_array(state->users, mask);
692			allow_bits_array(state->groups, mask);
693		} else {
694			deny_bits(&state->owner, mask);
695			deny_bits(&state->group, mask);
696			deny_bits(&state->other, mask);
697			deny_bits(&state->everyone, mask);
698			deny_bits_array(state->users, mask);
699			deny_bits_array(state->groups, mask);
700		}
701	}
702}
703
704static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
705		struct posix_acl **pacl, struct posix_acl **dpacl,
706		unsigned int flags)
707{
708	struct posix_acl_state effective_acl_state, default_acl_state;
709	struct nfs4_ace *ace;
710	int ret;
711
712	ret = init_state(&effective_acl_state, acl->naces);
713	if (ret)
714		return ret;
715	ret = init_state(&default_acl_state, acl->naces);
716	if (ret)
717		goto out_estate;
718	ret = -EINVAL;
719	for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
720		if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
721		    ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
722			goto out_dstate;
723		if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
724			goto out_dstate;
725		if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
726			process_one_v4_ace(&effective_acl_state, ace);
727			continue;
728		}
729		if (!(flags & NFS4_ACL_DIR))
730			goto out_dstate;
731		/*
732		 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
733		 * is set, we're effectively turning on the other.  That's OK,
734		 * according to rfc 3530.
735		 */
736		process_one_v4_ace(&default_acl_state, ace);
737
738		if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
739			process_one_v4_ace(&effective_acl_state, ace);
740	}
741	*pacl = posix_state_to_acl(&effective_acl_state, flags);
742	if (IS_ERR(*pacl)) {
743		ret = PTR_ERR(*pacl);
744		*pacl = NULL;
745		goto out_dstate;
746	}
747	*dpacl = posix_state_to_acl(&default_acl_state,
748						flags | NFS4_ACL_TYPE_DEFAULT);
749	if (IS_ERR(*dpacl)) {
750		ret = PTR_ERR(*dpacl);
751		*dpacl = NULL;
752		posix_acl_release(*pacl);
753		*pacl = NULL;
754		goto out_dstate;
755	}
756	sort_pacl(*pacl);
757	sort_pacl(*dpacl);
758	ret = 0;
759out_dstate:
760	free_state(&default_acl_state);
761out_estate:
762	free_state(&effective_acl_state);
763	return ret;
764}
765
766__be32
767nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
768		struct nfs4_acl *acl)
769{
770	__be32 error;
771	int host_error;
772	struct dentry *dentry;
773	struct inode *inode;
774	struct posix_acl *pacl = NULL, *dpacl = NULL;
775	unsigned int flags = 0;
776
777	/* Get inode */
778	error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
779	if (error)
780		return error;
781
782	dentry = fhp->fh_dentry;
783	inode = d_inode(dentry);
784
785	if (!inode->i_op->set_acl || !IS_POSIXACL(inode))
786		return nfserr_attrnotsupp;
787
788	if (S_ISDIR(inode->i_mode))
789		flags = NFS4_ACL_DIR;
790
791	host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
792	if (host_error == -EINVAL)
793		return nfserr_attrnotsupp;
794	if (host_error < 0)
795		goto out_nfserr;
796
797	host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS);
798	if (host_error < 0)
799		goto out_release;
800
801	if (S_ISDIR(inode->i_mode)) {
802		host_error = inode->i_op->set_acl(inode, dpacl,
803						  ACL_TYPE_DEFAULT);
804	}
805
806out_release:
807	posix_acl_release(pacl);
808	posix_acl_release(dpacl);
809out_nfserr:
810	if (host_error == -EOPNOTSUPP)
811		return nfserr_attrnotsupp;
812	else
813		return nfserrno(host_error);
814}
815
816
817static short
818ace2type(struct nfs4_ace *ace)
819{
820	switch (ace->whotype) {
821		case NFS4_ACL_WHO_NAMED:
822			return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
823					ACL_GROUP : ACL_USER);
824		case NFS4_ACL_WHO_OWNER:
825			return ACL_USER_OBJ;
826		case NFS4_ACL_WHO_GROUP:
827			return ACL_GROUP_OBJ;
828		case NFS4_ACL_WHO_EVERYONE:
829			return ACL_OTHER;
830	}
831	BUG();
832	return -1;
833}
834
835/*
836 * return the size of the struct nfs4_acl required to represent an acl
837 * with @entries entries.
838 */
839int nfs4_acl_bytes(int entries)
840{
841	return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
842}
843
844static struct {
845	char *string;
846	int   stringlen;
847	int type;
848} s2t_map[] = {
849	{
850		.string    = "OWNER@",
851		.stringlen = sizeof("OWNER@") - 1,
852		.type      = NFS4_ACL_WHO_OWNER,
853	},
854	{
855		.string    = "GROUP@",
856		.stringlen = sizeof("GROUP@") - 1,
857		.type      = NFS4_ACL_WHO_GROUP,
858	},
859	{
860		.string    = "EVERYONE@",
861		.stringlen = sizeof("EVERYONE@") - 1,
862		.type      = NFS4_ACL_WHO_EVERYONE,
863	},
864};
865
866int
867nfs4_acl_get_whotype(char *p, u32 len)
868{
869	int i;
870
871	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
872		if (s2t_map[i].stringlen == len &&
873				0 == memcmp(s2t_map[i].string, p, len))
874			return s2t_map[i].type;
875	}
876	return NFS4_ACL_WHO_NAMED;
877}
878
879__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
880{
881	__be32 *p;
882	int i;
883
884	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
885		if (s2t_map[i].type != who)
886			continue;
887		p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
888		if (!p)
889			return nfserr_resource;
890		p = xdr_encode_opaque(p, s2t_map[i].string,
891					s2t_map[i].stringlen);
892		return 0;
893	}
894	WARN_ON_ONCE(1);
895	return nfserr_serverfault;
896}
897