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pcmcia: add socket register data to sysfs for yenta devices
[linux-2.6.git] / fs / xfs / xfs_acl.c
blob92fd1d67f878f4fc0c3ed2a8b75a9ff65a3ba7a5
1 /*
2 * Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32
33 #include "xfs.h"
34
35 #include "xfs_inum.h"
36 #include "xfs_dir.h"
37 #include "xfs_dir2.h"
38 #include "xfs_alloc_btree.h"
39 #include "xfs_bmap_btree.h"
40 #include "xfs_ialloc_btree.h"
41 #include "xfs_btree.h"
42 #include "xfs_attr_sf.h"
43 #include "xfs_dir_sf.h"
44 #include "xfs_dir2_sf.h"
45 #include "xfs_dinode.h"
46 #include "xfs_inode.h"
47 #include "xfs_acl.h"
48 #include "xfs_mac.h"
49 #include "xfs_attr.h"
50
51 #include <linux/posix_acl_xattr.h>
52
53 STATIC int xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
54 STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
55 STATIC void xfs_acl_get_endian(xfs_acl_t *);
56 STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
57 STATIC int xfs_acl_invalid(xfs_acl_t *);
58 STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
59 STATIC void xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
60 STATIC void xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
61 STATIC int xfs_acl_allow_set(vnode_t *, int);
62
63 kmem_zone_t *xfs_acl_zone;
64
65
66 /*
67 * Test for existence of access ACL attribute as efficiently as possible.
68 */
69 int
70 xfs_acl_vhasacl_access(
71 vnode_t *vp)
72 {
73 int error;
74
75 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
76 return (error == 0);
77 }
78
79 /*
80 * Test for existence of default ACL attribute as efficiently as possible.
81 */
82 int
83 xfs_acl_vhasacl_default(
84 vnode_t *vp)
85 {
86 int error;
87
88 if (!VN_ISDIR(vp))
89 return 0;
90 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
91 return (error == 0);
92 }
93
94 /*
95 * Convert from extended attribute representation to in-memory for XFS.
96 */
97 STATIC int
98 posix_acl_xattr_to_xfs(
99 posix_acl_xattr_header *src,
100 size_t size,
101 xfs_acl_t *dest)
102 {
103 posix_acl_xattr_entry *src_entry;
104 xfs_acl_entry_t *dest_entry;
105 int n;
106
107 if (!src || !dest)
108 return EINVAL;
109
110 if (size < sizeof(posix_acl_xattr_header))
111 return EINVAL;
112
113 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
114 return EOPNOTSUPP;
115
116 memset(dest, 0, sizeof(xfs_acl_t));
117 dest->acl_cnt = posix_acl_xattr_count(size);
118 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
119 return EINVAL;
120
121 /*
122 * acl_set_file(3) may request that we set default ACLs with
123 * zero length -- defend (gracefully) against that here.
124 */
125 if (!dest->acl_cnt)
126 return 0;
127
128 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
129 dest_entry = &dest->acl_entry[0];
130
131 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
132 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
133 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
134 return EINVAL;
135 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
136 switch(dest_entry->ae_tag) {
137 case ACL_USER:
138 case ACL_GROUP:
139 dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
140 break;
141 case ACL_USER_OBJ:
142 case ACL_GROUP_OBJ:
143 case ACL_MASK:
144 case ACL_OTHER:
145 dest_entry->ae_id = ACL_UNDEFINED_ID;
146 break;
147 default:
148 return EINVAL;
149 }
150 }
151 if (xfs_acl_invalid(dest))
152 return EINVAL;
153
154 return 0;
155 }
156
157 /*
158 * Comparison function called from qsort().
159 * Primary key is ae_tag, secondary key is ae_id.
160 */
161 STATIC int
162 xfs_acl_entry_compare(
163 const void *va,
164 const void *vb)
165 {
166 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
167 *b = (xfs_acl_entry_t *)vb;
168
169 if (a->ae_tag == b->ae_tag)
170 return (a->ae_id - b->ae_id);
171 return (a->ae_tag - b->ae_tag);
172 }
173
174 /*
175 * Convert from in-memory XFS to extended attribute representation.
176 */
177 STATIC int
178 posix_acl_xfs_to_xattr(
179 xfs_acl_t *src,
180 posix_acl_xattr_header *dest,
181 size_t size)
182 {
183 int n;
184 size_t new_size = posix_acl_xattr_size(src->acl_cnt);
185 posix_acl_xattr_entry *dest_entry;
186 xfs_acl_entry_t *src_entry;
187
188 if (size < new_size)
189 return -ERANGE;
190
191 /* Need to sort src XFS ACL by <ae_tag,ae_id> */
192 qsort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
193 xfs_acl_entry_compare);
194
195 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
196 dest_entry = &dest->a_entries[0];
197 src_entry = &src->acl_entry[0];
198 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
199 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
200 if (_ACL_PERM_INVALID(src_entry->ae_perm))
201 return -EINVAL;
202 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
203 switch (src_entry->ae_tag) {
204 case ACL_USER:
205 case ACL_GROUP:
206 dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
207 break;
208 case ACL_USER_OBJ:
209 case ACL_GROUP_OBJ:
210 case ACL_MASK:
211 case ACL_OTHER:
212 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
213 break;
214 default:
215 return -EINVAL;
216 }
217 }
218 return new_size;
219 }
220
221 int
222 xfs_acl_vget(
223 vnode_t *vp,
224 void *acl,
225 size_t size,
226 int kind)
227 {
228 int error;
229 xfs_acl_t *xfs_acl = NULL;
230 posix_acl_xattr_header *ext_acl = acl;
231 int flags = 0;
232
233 VN_HOLD(vp);
234 if(size) {
235 if (!(_ACL_ALLOC(xfs_acl))) {
236 error = ENOMEM;
237 goto out;
238 }
239 memset(xfs_acl, 0, sizeof(xfs_acl_t));
240 } else
241 flags = ATTR_KERNOVAL;
242
243 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
244 if (error)
245 goto out;
246
247 if (!size) {
248 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
249 } else {
250 if (xfs_acl_invalid(xfs_acl)) {
251 error = EINVAL;
252 goto out;
253 }
254 if (kind == _ACL_TYPE_ACCESS) {
255 vattr_t va;
256
257 va.va_mask = XFS_AT_MODE;
258 VOP_GETATTR(vp, &va, 0, sys_cred, error);
259 if (error)
260 goto out;
261 xfs_acl_sync_mode(va.va_mode, xfs_acl);
262 }
263 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
264 }
265 out:
266 VN_RELE(vp);
267 if(xfs_acl)
268 _ACL_FREE(xfs_acl);
269 return -error;
270 }
271
272 int
273 xfs_acl_vremove(
274 vnode_t *vp,
275 int kind)
276 {
277 int error;
278
279 VN_HOLD(vp);
280 error = xfs_acl_allow_set(vp, kind);
281 if (!error) {
282 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
283 SGI_ACL_DEFAULT: SGI_ACL_FILE,
284 ATTR_ROOT, sys_cred, error);
285 if (error == ENOATTR)
286 error = 0; /* 'scool */
287 }
288 VN_RELE(vp);
289 return -error;
290 }
291
292 int
293 xfs_acl_vset(
294 vnode_t *vp,
295 void *acl,
296 size_t size,
297 int kind)
298 {
299 posix_acl_xattr_header *ext_acl = acl;
300 xfs_acl_t *xfs_acl;
301 int error;
302 int basicperms = 0; /* more than std unix perms? */
303
304 if (!acl)
305 return -EINVAL;
306
307 if (!(_ACL_ALLOC(xfs_acl)))
308 return -ENOMEM;
309
310 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
311 if (error) {
312 _ACL_FREE(xfs_acl);
313 return -error;
314 }
315 if (!xfs_acl->acl_cnt) {
316 _ACL_FREE(xfs_acl);
317 return 0;
318 }
319
320 VN_HOLD(vp);
321 error = xfs_acl_allow_set(vp, kind);
322 if (error)
323 goto out;
324
325 /* Incoming ACL exists, set file mode based on its value */
326 if (kind == _ACL_TYPE_ACCESS)
327 xfs_acl_setmode(vp, xfs_acl, &basicperms);
328
329 /*
330 * If we have more than std unix permissions, set up the actual attr.
331 * Otherwise, delete any existing attr. This prevents us from
332 * having actual attrs for permissions that can be stored in the
333 * standard permission bits.
334 */
335 if (!basicperms) {
336 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
337 } else {
338 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
339 }
340
341 out:
342 VN_RELE(vp);
343 _ACL_FREE(xfs_acl);
344 return -error;
345 }
346
347 int
348 xfs_acl_iaccess(
349 xfs_inode_t *ip,
350 mode_t mode,
351 cred_t *cr)
352 {
353 xfs_acl_t *acl;
354 int rval;
355
356 if (!(_ACL_ALLOC(acl)))
357 return -1;
358
359 /* If the file has no ACL return -1. */
360 rval = sizeof(xfs_acl_t);
361 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
362 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
363 _ACL_FREE(acl);
364 return -1;
365 }
366 xfs_acl_get_endian(acl);
367
368 /* If the file has an empty ACL return -1. */
369 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
370 _ACL_FREE(acl);
371 return -1;
372 }
373
374 /* Synchronize ACL with mode bits */
375 xfs_acl_sync_mode(ip->i_d.di_mode, acl);
376
377 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
378 _ACL_FREE(acl);
379 return rval;
380 }
381
382 STATIC int
383 xfs_acl_allow_set(
384 vnode_t *vp,
385 int kind)
386 {
387 vattr_t va;
388 int error;
389
390 if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
391 return EPERM;
392 if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
393 return ENOTDIR;
394 if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
395 return EROFS;
396 va.va_mask = XFS_AT_UID;
397 VOP_GETATTR(vp, &va, 0, NULL, error);
398 if (error)
399 return error;
400 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
401 return EPERM;
402 return error;
403 }
404
405 /*
406 * The access control process to determine the access permission:
407 * if uid == file owner id, use the file owner bits.
408 * if gid == file owner group id, use the file group bits.
409 * scan ACL for a maching user or group, and use matched entry
410 * permission. Use total permissions of all matching group entries,
411 * until all acl entries are exhausted. The final permission produced
412 * by matching acl entry or entries needs to be & with group permission.
413 * if not owner, owning group, or matching entry in ACL, use file
414 * other bits.
415 */
416 STATIC int
417 xfs_acl_capability_check(
418 mode_t mode,
419 cred_t *cr)
420 {
421 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
422 return EACCES;
423 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
424 return EACCES;
425 if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
426 return EACCES;
427
428 return 0;
429 }
430
431 /*
432 * Note: cr is only used here for the capability check if the ACL test fails.
433 * It is not used to find out the credentials uid or groups etc, as was
434 * done in IRIX. It is assumed that the uid and groups for the current
435 * thread are taken from "current" instead of the cr parameter.
436 */
437 STATIC int
438 xfs_acl_access(
439 uid_t fuid,
440 gid_t fgid,
441 xfs_acl_t *fap,
442 mode_t md,
443 cred_t *cr)
444 {
445 xfs_acl_entry_t matched;
446 int i, allows;
447 int maskallows = -1; /* true, but not 1, either */
448 int seen_userobj = 0;
449
450 matched.ae_tag = 0; /* Invalid type */
451 md >>= 6; /* Normalize the bits for comparison */
452
453 for (i = 0; i < fap->acl_cnt; i++) {
454 /*
455 * Break out if we've got a user_obj entry or
456 * a user entry and the mask (and have processed USER_OBJ)
457 */
458 if (matched.ae_tag == ACL_USER_OBJ)
459 break;
460 if (matched.ae_tag == ACL_USER) {
461 if (maskallows != -1 && seen_userobj)
462 break;
463 if (fap->acl_entry[i].ae_tag != ACL_MASK &&
464 fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
465 continue;
466 }
467 /* True if this entry allows the requested access */
468 allows = ((fap->acl_entry[i].ae_perm & md) == md);
469
470 switch (fap->acl_entry[i].ae_tag) {
471 case ACL_USER_OBJ:
472 seen_userobj = 1;
473 if (fuid != current->fsuid)
474 continue;
475 matched.ae_tag = ACL_USER_OBJ;
476 matched.ae_perm = allows;
477 break;
478 case ACL_USER:
479 if (fap->acl_entry[i].ae_id != current->fsuid)
480 continue;
481 matched.ae_tag = ACL_USER;
482 matched.ae_perm = allows;
483 break;
484 case ACL_GROUP_OBJ:
485 if ((matched.ae_tag == ACL_GROUP_OBJ ||
486 matched.ae_tag == ACL_GROUP) && !allows)
487 continue;
488 if (!in_group_p(fgid))
489 continue;
490 matched.ae_tag = ACL_GROUP_OBJ;
491 matched.ae_perm = allows;
492 break;
493 case ACL_GROUP:
494 if ((matched.ae_tag == ACL_GROUP_OBJ ||
495 matched.ae_tag == ACL_GROUP) && !allows)
496 continue;
497 if (!in_group_p(fap->acl_entry[i].ae_id))
498 continue;
499 matched.ae_tag = ACL_GROUP;
500 matched.ae_perm = allows;
501 break;
502 case ACL_MASK:
503 maskallows = allows;
504 break;
505 case ACL_OTHER:
506 if (matched.ae_tag != 0)
507 continue;
508 matched.ae_tag = ACL_OTHER;
509 matched.ae_perm = allows;
510 break;
511 }
512 }
513 /*
514 * First possibility is that no matched entry allows access.
515 * The capability to override DAC may exist, so check for it.
516 */
517 switch (matched.ae_tag) {
518 case ACL_OTHER:
519 case ACL_USER_OBJ:
520 if (matched.ae_perm)
521 return 0;
522 break;
523 case ACL_USER:
524 case ACL_GROUP_OBJ:
525 case ACL_GROUP:
526 if (maskallows && matched.ae_perm)
527 return 0;
528 break;
529 case 0:
530 break;
531 }
532
533 return xfs_acl_capability_check(md, cr);
534 }
535
536 /*
537 * ACL validity checker.
538 * This acl validation routine checks each ACL entry read in makes sense.
539 */
540 STATIC int
541 xfs_acl_invalid(
542 xfs_acl_t *aclp)
543 {
544 xfs_acl_entry_t *entry, *e;
545 int user = 0, group = 0, other = 0, mask = 0;
546 int mask_required = 0;
547 int i, j;
548
549 if (!aclp)
550 goto acl_invalid;
551
552 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
553 goto acl_invalid;
554
555 for (i = 0; i < aclp->acl_cnt; i++) {
556 entry = &aclp->acl_entry[i];
557 switch (entry->ae_tag) {
558 case ACL_USER_OBJ:
559 if (user++)
560 goto acl_invalid;
561 break;
562 case ACL_GROUP_OBJ:
563 if (group++)
564 goto acl_invalid;
565 break;
566 case ACL_OTHER:
567 if (other++)
568 goto acl_invalid;
569 break;
570 case ACL_USER:
571 case ACL_GROUP:
572 for (j = i + 1; j < aclp->acl_cnt; j++) {
573 e = &aclp->acl_entry[j];
574 if (e->ae_id == entry->ae_id &&
575 e->ae_tag == entry->ae_tag)
576 goto acl_invalid;
577 }
578 mask_required++;
579 break;
580 case ACL_MASK:
581 if (mask++)
582 goto acl_invalid;
583 break;
584 default:
585 goto acl_invalid;
586 }
587 }
588 if (!user || !group || !other || (mask_required && !mask))
589 goto acl_invalid;
590 else
591 return 0;
592 acl_invalid:
593 return EINVAL;
594 }
595
596 /*
597 * Do ACL endian conversion.
598 */
599 STATIC void
600 xfs_acl_get_endian(
601 xfs_acl_t *aclp)
602 {
603 xfs_acl_entry_t *ace, *end;
604
605 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
606 end = &aclp->acl_entry[0]+aclp->acl_cnt;
607 for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
608 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
609 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
610 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
611 }
612 }
613
614 /*
615 * Get the ACL from the EA and do endian conversion.
616 */
617 STATIC void
618 xfs_acl_get_attr(
619 vnode_t *vp,
620 xfs_acl_t *aclp,
621 int kind,
622 int flags,
623 int *error)
624 {
625 int len = sizeof(xfs_acl_t);
626
627 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
628 flags |= ATTR_ROOT;
629 VOP_ATTR_GET(vp,
630 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
631 (char *)aclp, &len, flags, sys_cred, *error);
632 if (*error || (flags & ATTR_KERNOVAL))
633 return;
634 xfs_acl_get_endian(aclp);
635 }
636
637 /*
638 * Set the EA with the ACL and do endian conversion.
639 */
640 STATIC void
641 xfs_acl_set_attr(
642 vnode_t *vp,
643 xfs_acl_t *aclp,
644 int kind,
645 int *error)
646 {
647 xfs_acl_entry_t *ace, *newace, *end;
648 xfs_acl_t *newacl;
649 int len;
650
651 if (!(_ACL_ALLOC(newacl))) {
652 *error = ENOMEM;
653 return;
654 }
655
656 len = sizeof(xfs_acl_t) -
657 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
658 end = &aclp->acl_entry[0]+aclp->acl_cnt;
659 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
660 ace < end;
661 ace++, newace++) {
662 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
663 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
664 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
665 }
666 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
667 VOP_ATTR_SET(vp,
668 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
669 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
670 _ACL_FREE(newacl);
671 }
672
673 int
674 xfs_acl_vtoacl(
675 vnode_t *vp,
676 xfs_acl_t *access_acl,
677 xfs_acl_t *default_acl)
678 {
679 vattr_t va;
680 int error = 0;
681
682 if (access_acl) {
683 /*
684 * Get the Access ACL and the mode. If either cannot
685 * be obtained for some reason, invalidate the access ACL.
686 */
687 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
688 if (!error) {
689 /* Got the ACL, need the mode... */
690 va.va_mask = XFS_AT_MODE;
691 VOP_GETATTR(vp, &va, 0, sys_cred, error);
692 }
693
694 if (error)
695 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
696 else /* We have a good ACL and the file mode, synchronize. */
697 xfs_acl_sync_mode(va.va_mode, access_acl);
698 }
699
700 if (default_acl) {
701 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
702 if (error)
703 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
704 }
705 return error;
706 }
707
708 /*
709 * This function retrieves the parent directory's acl, processes it
710 * and lets the child inherit the acl(s) that it should.
711 */
712 int
713 xfs_acl_inherit(
714 vnode_t *vp,
715 vattr_t *vap,
716 xfs_acl_t *pdaclp)
717 {
718 xfs_acl_t *cacl;
719 int error = 0;
720 int basicperms = 0;
721
722 /*
723 * If the parent does not have a default ACL, or it's an
724 * invalid ACL, we're done.
725 */
726 if (!vp)
727 return 0;
728 if (!pdaclp || xfs_acl_invalid(pdaclp))
729 return 0;
730
731 /*
732 * Copy the default ACL of the containing directory to
733 * the access ACL of the new file and use the mode that
734 * was passed in to set up the correct initial values for
735 * the u::,g::[m::], and o:: entries. This is what makes
736 * umask() "work" with ACL's.
737 */
738
739 if (!(_ACL_ALLOC(cacl)))
740 return ENOMEM;
741
742 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
743 xfs_acl_filter_mode(vap->va_mode, cacl);
744 xfs_acl_setmode(vp, cacl, &basicperms);
745
746 /*
747 * Set the Default and Access ACL on the file. The mode is already
748 * set on the file, so we don't need to worry about that.
749 *
750 * If the new file is a directory, its default ACL is a copy of
751 * the containing directory's default ACL.
752 */
753 if (VN_ISDIR(vp))
754 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
755 if (!error && !basicperms)
756 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
757 _ACL_FREE(cacl);
758 return error;
759 }
760
761 /*
762 * Set up the correct mode on the file based on the supplied ACL. This
763 * makes sure that the mode on the file reflects the state of the
764 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
765 * the ACL is going to get the permissions for these entries, we must
766 * synchronize the mode whenever we set the ACL on a file.
767 */
768 STATIC int
769 xfs_acl_setmode(
770 vnode_t *vp,
771 xfs_acl_t *acl,
772 int *basicperms)
773 {
774 vattr_t va;
775 xfs_acl_entry_t *ap;
776 xfs_acl_entry_t *gap = NULL;
777 int i, error, nomask = 1;
778
779 *basicperms = 1;
780
781 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
782 return 0;
783
784 /*
785 * Copy the u::, g::, o::, and m:: bits from the ACL into the
786 * mode. The m:: bits take precedence over the g:: bits.
787 */
788 va.va_mask = XFS_AT_MODE;
789 VOP_GETATTR(vp, &va, 0, sys_cred, error);
790 if (error)
791 return error;
792
793 va.va_mask = XFS_AT_MODE;
794 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
795 ap = acl->acl_entry;
796 for (i = 0; i < acl->acl_cnt; ++i) {
797 switch (ap->ae_tag) {
798 case ACL_USER_OBJ:
799 va.va_mode |= ap->ae_perm << 6;
800 break;
801 case ACL_GROUP_OBJ:
802 gap = ap;
803 break;
804 case ACL_MASK: /* more than just standard modes */
805 nomask = 0;
806 va.va_mode |= ap->ae_perm << 3;
807 *basicperms = 0;
808 break;
809 case ACL_OTHER:
810 va.va_mode |= ap->ae_perm;
811 break;
812 default: /* more than just standard modes */
813 *basicperms = 0;
814 break;
815 }
816 ap++;
817 }
818
819 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
820 if (gap && nomask)
821 va.va_mode |= gap->ae_perm << 3;
822
823 VOP_SETATTR(vp, &va, 0, sys_cred, error);
824 return error;
825 }
826
827 /*
828 * The permissions for the special ACL entries (u::, g::[m::], o::) are
829 * actually stored in the file mode (if there is both a group and a mask,
830 * the group is stored in the ACL entry and the mask is stored on the file).
831 * This allows the mode to remain automatically in sync with the ACL without
832 * the need for a call-back to the ACL system at every point where the mode
833 * could change. This function takes the permissions from the specified mode
834 * and places it in the supplied ACL.
835 *
836 * This implementation draws its validity from the fact that, when the ACL
837 * was assigned, the mode was copied from the ACL.
838 * If the mode did not change, therefore, the mode remains exactly what was
839 * taken from the special ACL entries at assignment.
840 * If a subsequent chmod() was done, the POSIX spec says that the change in
841 * mode must cause an update to the ACL seen at user level and used for
842 * access checks. Before and after a mode change, therefore, the file mode
843 * most accurately reflects what the special ACL entries should permit/deny.
844 *
845 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
846 * the existing mode bits will override whatever is in the
847 * ACL. Similarly, if there is a pre-existing ACL that was
848 * never in sync with its mode (owing to a bug in 6.5 and
849 * before), it will now magically (or mystically) be
850 * synchronized. This could cause slight astonishment, but
851 * it is better than inconsistent permissions.
852 *
853 * The supplied ACL is a template that may contain any combination
854 * of special entries. These are treated as place holders when we fill
855 * out the ACL. This routine does not add or remove special entries, it
856 * simply unites each special entry with its associated set of permissions.
857 */
858 STATIC void
859 xfs_acl_sync_mode(
860 mode_t mode,
861 xfs_acl_t *acl)
862 {
863 int i, nomask = 1;
864 xfs_acl_entry_t *ap;
865 xfs_acl_entry_t *gap = NULL;
866
867 /*
868 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
869 * be set instead of the GROUP entry, if there is a MASK.
870 */
871 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
872 switch (ap->ae_tag) {
873 case ACL_USER_OBJ:
874 ap->ae_perm = (mode >> 6) & 0x7;
875 break;
876 case ACL_GROUP_OBJ:
877 gap = ap;
878 break;
879 case ACL_MASK:
880 nomask = 0;
881 ap->ae_perm = (mode >> 3) & 0x7;
882 break;
883 case ACL_OTHER:
884 ap->ae_perm = mode & 0x7;
885 break;
886 default:
887 break;
888 }
889 }
890 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
891 if (gap && nomask)
892 gap->ae_perm = (mode >> 3) & 0x7;
893 }
894
895 /*
896 * When inheriting an Access ACL from a directory Default ACL,
897 * the ACL bits are set to the intersection of the ACL default
898 * permission bits and the file permission bits in mode. If there
899 * are no permission bits on the file then we must not give them
900 * the ACL. This is what what makes umask() work with ACLs.
901 */
902 STATIC void
903 xfs_acl_filter_mode(
904 mode_t mode,
905 xfs_acl_t *acl)
906 {
907 int i, nomask = 1;
908 xfs_acl_entry_t *ap;
909 xfs_acl_entry_t *gap = NULL;
910
911 /*
912 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
913 * be merged with GROUP entry, if there is a MASK.
914 */
915 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
916 switch (ap->ae_tag) {
917 case ACL_USER_OBJ:
918 ap->ae_perm &= (mode >> 6) & 0x7;
919 break;
920 case ACL_GROUP_OBJ:
921 gap = ap;
922 break;
923 case ACL_MASK:
924 nomask = 0;
925 ap->ae_perm &= (mode >> 3) & 0x7;
926 break;
927 case ACL_OTHER:
928 ap->ae_perm &= mode & 0x7;
929 break;
930 default:
931 break;
932 }
933 }
934 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
935 if (gap && nomask)
936 gap->ae_perm &= (mode >> 3) & 0x7;
937 }
Linus' kernel tree