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kbuild: tags file generation fixup
[linux-2.6/linux-2.6-openrd.git] / fs / xfs / xfs_acl.c
blobcc9c91b9e77197ffdec8c497200c3ea4f64dc586
1 /*
2 * Copyright (c) 2001-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_inum.h"
23 #include "xfs_ag.h"
24 #include "xfs_dir.h"
25 #include "xfs_dir2.h"
26 #include "xfs_bmap_btree.h"
27 #include "xfs_alloc_btree.h"
28 #include "xfs_ialloc_btree.h"
29 #include "xfs_dir_sf.h"
30 #include "xfs_dir2_sf.h"
31 #include "xfs_attr_sf.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_btree.h"
35 #include "xfs_acl.h"
36 #include "xfs_mac.h"
37 #include "xfs_attr.h"
38
39 #include <linux/posix_acl_xattr.h>
40
41 STATIC int xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
42 STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
43 STATIC void xfs_acl_get_endian(xfs_acl_t *);
44 STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
45 STATIC int xfs_acl_invalid(xfs_acl_t *);
46 STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
47 STATIC void xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
48 STATIC void xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
49 STATIC int xfs_acl_allow_set(vnode_t *, int);
50
51 kmem_zone_t *xfs_acl_zone;
52
53
54 /*
55 * Test for existence of access ACL attribute as efficiently as possible.
56 */
57 int
58 xfs_acl_vhasacl_access(
59 vnode_t *vp)
60 {
61 int error;
62
63 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
64 return (error == 0);
65 }
66
67 /*
68 * Test for existence of default ACL attribute as efficiently as possible.
69 */
70 int
71 xfs_acl_vhasacl_default(
72 vnode_t *vp)
73 {
74 int error;
75
76 if (!VN_ISDIR(vp))
77 return 0;
78 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
79 return (error == 0);
80 }
81
82 /*
83 * Convert from extended attribute representation to in-memory for XFS.
84 */
85 STATIC int
86 posix_acl_xattr_to_xfs(
87 posix_acl_xattr_header *src,
88 size_t size,
89 xfs_acl_t *dest)
90 {
91 posix_acl_xattr_entry *src_entry;
92 xfs_acl_entry_t *dest_entry;
93 int n;
94
95 if (!src || !dest)
96 return EINVAL;
97
98 if (size < sizeof(posix_acl_xattr_header))
99 return EINVAL;
100
101 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
102 return EOPNOTSUPP;
103
104 memset(dest, 0, sizeof(xfs_acl_t));
105 dest->acl_cnt = posix_acl_xattr_count(size);
106 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
107 return EINVAL;
108
109 /*
110 * acl_set_file(3) may request that we set default ACLs with
111 * zero length -- defend (gracefully) against that here.
112 */
113 if (!dest->acl_cnt)
114 return 0;
115
116 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
117 dest_entry = &dest->acl_entry[0];
118
119 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
120 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
121 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
122 return EINVAL;
123 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
124 switch(dest_entry->ae_tag) {
125 case ACL_USER:
126 case ACL_GROUP:
127 dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
128 break;
129 case ACL_USER_OBJ:
130 case ACL_GROUP_OBJ:
131 case ACL_MASK:
132 case ACL_OTHER:
133 dest_entry->ae_id = ACL_UNDEFINED_ID;
134 break;
135 default:
136 return EINVAL;
137 }
138 }
139 if (xfs_acl_invalid(dest))
140 return EINVAL;
141
142 return 0;
143 }
144
145 /*
146 * Comparison function called from xfs_sort().
147 * Primary key is ae_tag, secondary key is ae_id.
148 */
149 STATIC int
150 xfs_acl_entry_compare(
151 const void *va,
152 const void *vb)
153 {
154 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
155 *b = (xfs_acl_entry_t *)vb;
156
157 if (a->ae_tag == b->ae_tag)
158 return (a->ae_id - b->ae_id);
159 return (a->ae_tag - b->ae_tag);
160 }
161
162 /*
163 * Convert from in-memory XFS to extended attribute representation.
164 */
165 STATIC int
166 posix_acl_xfs_to_xattr(
167 xfs_acl_t *src,
168 posix_acl_xattr_header *dest,
169 size_t size)
170 {
171 int n;
172 size_t new_size = posix_acl_xattr_size(src->acl_cnt);
173 posix_acl_xattr_entry *dest_entry;
174 xfs_acl_entry_t *src_entry;
175
176 if (size < new_size)
177 return -ERANGE;
178
179 /* Need to sort src XFS ACL by <ae_tag,ae_id> */
180 xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
181 xfs_acl_entry_compare);
182
183 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
184 dest_entry = &dest->a_entries[0];
185 src_entry = &src->acl_entry[0];
186 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
187 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
188 if (_ACL_PERM_INVALID(src_entry->ae_perm))
189 return -EINVAL;
190 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
191 switch (src_entry->ae_tag) {
192 case ACL_USER:
193 case ACL_GROUP:
194 dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
195 break;
196 case ACL_USER_OBJ:
197 case ACL_GROUP_OBJ:
198 case ACL_MASK:
199 case ACL_OTHER:
200 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
201 break;
202 default:
203 return -EINVAL;
204 }
205 }
206 return new_size;
207 }
208
209 int
210 xfs_acl_vget(
211 vnode_t *vp,
212 void *acl,
213 size_t size,
214 int kind)
215 {
216 int error;
217 xfs_acl_t *xfs_acl = NULL;
218 posix_acl_xattr_header *ext_acl = acl;
219 int flags = 0;
220
221 VN_HOLD(vp);
222 if(size) {
223 if (!(_ACL_ALLOC(xfs_acl))) {
224 error = ENOMEM;
225 goto out;
226 }
227 memset(xfs_acl, 0, sizeof(xfs_acl_t));
228 } else
229 flags = ATTR_KERNOVAL;
230
231 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
232 if (error)
233 goto out;
234
235 if (!size) {
236 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
237 } else {
238 if (xfs_acl_invalid(xfs_acl)) {
239 error = EINVAL;
240 goto out;
241 }
242 if (kind == _ACL_TYPE_ACCESS) {
243 vattr_t va;
244
245 va.va_mask = XFS_AT_MODE;
246 VOP_GETATTR(vp, &va, 0, sys_cred, error);
247 if (error)
248 goto out;
249 xfs_acl_sync_mode(va.va_mode, xfs_acl);
250 }
251 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
252 }
253 out:
254 VN_RELE(vp);
255 if(xfs_acl)
256 _ACL_FREE(xfs_acl);
257 return -error;
258 }
259
260 int
261 xfs_acl_vremove(
262 vnode_t *vp,
263 int kind)
264 {
265 int error;
266
267 VN_HOLD(vp);
268 error = xfs_acl_allow_set(vp, kind);
269 if (!error) {
270 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
271 SGI_ACL_DEFAULT: SGI_ACL_FILE,
272 ATTR_ROOT, sys_cred, error);
273 if (error == ENOATTR)
274 error = 0; /* 'scool */
275 }
276 VN_RELE(vp);
277 return -error;
278 }
279
280 int
281 xfs_acl_vset(
282 vnode_t *vp,
283 void *acl,
284 size_t size,
285 int kind)
286 {
287 posix_acl_xattr_header *ext_acl = acl;
288 xfs_acl_t *xfs_acl;
289 int error;
290 int basicperms = 0; /* more than std unix perms? */
291
292 if (!acl)
293 return -EINVAL;
294
295 if (!(_ACL_ALLOC(xfs_acl)))
296 return -ENOMEM;
297
298 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
299 if (error) {
300 _ACL_FREE(xfs_acl);
301 return -error;
302 }
303 if (!xfs_acl->acl_cnt) {
304 _ACL_FREE(xfs_acl);
305 return 0;
306 }
307
308 VN_HOLD(vp);
309 error = xfs_acl_allow_set(vp, kind);
310 if (error)
311 goto out;
312
313 /* Incoming ACL exists, set file mode based on its value */
314 if (kind == _ACL_TYPE_ACCESS)
315 xfs_acl_setmode(vp, xfs_acl, &basicperms);
316
317 /*
318 * If we have more than std unix permissions, set up the actual attr.
319 * Otherwise, delete any existing attr. This prevents us from
320 * having actual attrs for permissions that can be stored in the
321 * standard permission bits.
322 */
323 if (!basicperms) {
324 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
325 } else {
326 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
327 }
328
329 out:
330 VN_RELE(vp);
331 _ACL_FREE(xfs_acl);
332 return -error;
333 }
334
335 int
336 xfs_acl_iaccess(
337 xfs_inode_t *ip,
338 mode_t mode,
339 cred_t *cr)
340 {
341 xfs_acl_t *acl;
342 int rval;
343
344 if (!(_ACL_ALLOC(acl)))
345 return -1;
346
347 /* If the file has no ACL return -1. */
348 rval = sizeof(xfs_acl_t);
349 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
350 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
351 _ACL_FREE(acl);
352 return -1;
353 }
354 xfs_acl_get_endian(acl);
355
356 /* If the file has an empty ACL return -1. */
357 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
358 _ACL_FREE(acl);
359 return -1;
360 }
361
362 /* Synchronize ACL with mode bits */
363 xfs_acl_sync_mode(ip->i_d.di_mode, acl);
364
365 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
366 _ACL_FREE(acl);
367 return rval;
368 }
369
370 STATIC int
371 xfs_acl_allow_set(
372 vnode_t *vp,
373 int kind)
374 {
375 vattr_t va;
376 int error;
377
378 if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
379 return EPERM;
380 if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
381 return ENOTDIR;
382 if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
383 return EROFS;
384 va.va_mask = XFS_AT_UID;
385 VOP_GETATTR(vp, &va, 0, NULL, error);
386 if (error)
387 return error;
388 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
389 return EPERM;
390 return error;
391 }
392
393 /*
394 * The access control process to determine the access permission:
395 * if uid == file owner id, use the file owner bits.
396 * if gid == file owner group id, use the file group bits.
397 * scan ACL for a maching user or group, and use matched entry
398 * permission. Use total permissions of all matching group entries,
399 * until all acl entries are exhausted. The final permission produced
400 * by matching acl entry or entries needs to be & with group permission.
401 * if not owner, owning group, or matching entry in ACL, use file
402 * other bits.
403 */
404 STATIC int
405 xfs_acl_capability_check(
406 mode_t mode,
407 cred_t *cr)
408 {
409 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
410 return EACCES;
411 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
412 return EACCES;
413 if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
414 return EACCES;
415
416 return 0;
417 }
418
419 /*
420 * Note: cr is only used here for the capability check if the ACL test fails.
421 * It is not used to find out the credentials uid or groups etc, as was
422 * done in IRIX. It is assumed that the uid and groups for the current
423 * thread are taken from "current" instead of the cr parameter.
424 */
425 STATIC int
426 xfs_acl_access(
427 uid_t fuid,
428 gid_t fgid,
429 xfs_acl_t *fap,
430 mode_t md,
431 cred_t *cr)
432 {
433 xfs_acl_entry_t matched;
434 int i, allows;
435 int maskallows = -1; /* true, but not 1, either */
436 int seen_userobj = 0;
437
438 matched.ae_tag = 0; /* Invalid type */
439 matched.ae_perm = 0;
440 md >>= 6; /* Normalize the bits for comparison */
441
442 for (i = 0; i < fap->acl_cnt; i++) {
443 /*
444 * Break out if we've got a user_obj entry or
445 * a user entry and the mask (and have processed USER_OBJ)
446 */
447 if (matched.ae_tag == ACL_USER_OBJ)
448 break;
449 if (matched.ae_tag == ACL_USER) {
450 if (maskallows != -1 && seen_userobj)
451 break;
452 if (fap->acl_entry[i].ae_tag != ACL_MASK &&
453 fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
454 continue;
455 }
456 /* True if this entry allows the requested access */
457 allows = ((fap->acl_entry[i].ae_perm & md) == md);
458
459 switch (fap->acl_entry[i].ae_tag) {
460 case ACL_USER_OBJ:
461 seen_userobj = 1;
462 if (fuid != current->fsuid)
463 continue;
464 matched.ae_tag = ACL_USER_OBJ;
465 matched.ae_perm = allows;
466 break;
467 case ACL_USER:
468 if (fap->acl_entry[i].ae_id != current->fsuid)
469 continue;
470 matched.ae_tag = ACL_USER;
471 matched.ae_perm = allows;
472 break;
473 case ACL_GROUP_OBJ:
474 if ((matched.ae_tag == ACL_GROUP_OBJ ||
475 matched.ae_tag == ACL_GROUP) && !allows)
476 continue;
477 if (!in_group_p(fgid))
478 continue;
479 matched.ae_tag = ACL_GROUP_OBJ;
480 matched.ae_perm = allows;
481 break;
482 case ACL_GROUP:
483 if ((matched.ae_tag == ACL_GROUP_OBJ ||
484 matched.ae_tag == ACL_GROUP) && !allows)
485 continue;
486 if (!in_group_p(fap->acl_entry[i].ae_id))
487 continue;
488 matched.ae_tag = ACL_GROUP;
489 matched.ae_perm = allows;
490 break;
491 case ACL_MASK:
492 maskallows = allows;
493 break;
494 case ACL_OTHER:
495 if (matched.ae_tag != 0)
496 continue;
497 matched.ae_tag = ACL_OTHER;
498 matched.ae_perm = allows;
499 break;
500 }
501 }
502 /*
503 * First possibility is that no matched entry allows access.
504 * The capability to override DAC may exist, so check for it.
505 */
506 switch (matched.ae_tag) {
507 case ACL_OTHER:
508 case ACL_USER_OBJ:
509 if (matched.ae_perm)
510 return 0;
511 break;
512 case ACL_USER:
513 case ACL_GROUP_OBJ:
514 case ACL_GROUP:
515 if (maskallows && matched.ae_perm)
516 return 0;
517 break;
518 case 0:
519 break;
520 }
521
522 return xfs_acl_capability_check(md, cr);
523 }
524
525 /*
526 * ACL validity checker.
527 * This acl validation routine checks each ACL entry read in makes sense.
528 */
529 STATIC int
530 xfs_acl_invalid(
531 xfs_acl_t *aclp)
532 {
533 xfs_acl_entry_t *entry, *e;
534 int user = 0, group = 0, other = 0, mask = 0;
535 int mask_required = 0;
536 int i, j;
537
538 if (!aclp)
539 goto acl_invalid;
540
541 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
542 goto acl_invalid;
543
544 for (i = 0; i < aclp->acl_cnt; i++) {
545 entry = &aclp->acl_entry[i];
546 switch (entry->ae_tag) {
547 case ACL_USER_OBJ:
548 if (user++)
549 goto acl_invalid;
550 break;
551 case ACL_GROUP_OBJ:
552 if (group++)
553 goto acl_invalid;
554 break;
555 case ACL_OTHER:
556 if (other++)
557 goto acl_invalid;
558 break;
559 case ACL_USER:
560 case ACL_GROUP:
561 for (j = i + 1; j < aclp->acl_cnt; j++) {
562 e = &aclp->acl_entry[j];
563 if (e->ae_id == entry->ae_id &&
564 e->ae_tag == entry->ae_tag)
565 goto acl_invalid;
566 }
567 mask_required++;
568 break;
569 case ACL_MASK:
570 if (mask++)
571 goto acl_invalid;
572 break;
573 default:
574 goto acl_invalid;
575 }
576 }
577 if (!user || !group || !other || (mask_required && !mask))
578 goto acl_invalid;
579 else
580 return 0;
581 acl_invalid:
582 return EINVAL;
583 }
584
585 /*
586 * Do ACL endian conversion.
587 */
588 STATIC void
589 xfs_acl_get_endian(
590 xfs_acl_t *aclp)
591 {
592 xfs_acl_entry_t *ace, *end;
593
594 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
595 end = &aclp->acl_entry[0]+aclp->acl_cnt;
596 for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
597 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
598 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
599 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
600 }
601 }
602
603 /*
604 * Get the ACL from the EA and do endian conversion.
605 */
606 STATIC void
607 xfs_acl_get_attr(
608 vnode_t *vp,
609 xfs_acl_t *aclp,
610 int kind,
611 int flags,
612 int *error)
613 {
614 int len = sizeof(xfs_acl_t);
615
616 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
617 flags |= ATTR_ROOT;
618 VOP_ATTR_GET(vp,
619 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
620 (char *)aclp, &len, flags, sys_cred, *error);
621 if (*error || (flags & ATTR_KERNOVAL))
622 return;
623 xfs_acl_get_endian(aclp);
624 }
625
626 /*
627 * Set the EA with the ACL and do endian conversion.
628 */
629 STATIC void
630 xfs_acl_set_attr(
631 vnode_t *vp,
632 xfs_acl_t *aclp,
633 int kind,
634 int *error)
635 {
636 xfs_acl_entry_t *ace, *newace, *end;
637 xfs_acl_t *newacl;
638 int len;
639
640 if (!(_ACL_ALLOC(newacl))) {
641 *error = ENOMEM;
642 return;
643 }
644
645 len = sizeof(xfs_acl_t) -
646 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
647 end = &aclp->acl_entry[0]+aclp->acl_cnt;
648 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
649 ace < end;
650 ace++, newace++) {
651 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
652 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
653 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
654 }
655 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
656 VOP_ATTR_SET(vp,
657 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
658 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
659 _ACL_FREE(newacl);
660 }
661
662 int
663 xfs_acl_vtoacl(
664 vnode_t *vp,
665 xfs_acl_t *access_acl,
666 xfs_acl_t *default_acl)
667 {
668 vattr_t va;
669 int error = 0;
670
671 if (access_acl) {
672 /*
673 * Get the Access ACL and the mode. If either cannot
674 * be obtained for some reason, invalidate the access ACL.
675 */
676 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
677 if (!error) {
678 /* Got the ACL, need the mode... */
679 va.va_mask = XFS_AT_MODE;
680 VOP_GETATTR(vp, &va, 0, sys_cred, error);
681 }
682
683 if (error)
684 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
685 else /* We have a good ACL and the file mode, synchronize. */
686 xfs_acl_sync_mode(va.va_mode, access_acl);
687 }
688
689 if (default_acl) {
690 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
691 if (error)
692 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
693 }
694 return error;
695 }
696
697 /*
698 * This function retrieves the parent directory's acl, processes it
699 * and lets the child inherit the acl(s) that it should.
700 */
701 int
702 xfs_acl_inherit(
703 vnode_t *vp,
704 vattr_t *vap,
705 xfs_acl_t *pdaclp)
706 {
707 xfs_acl_t *cacl;
708 int error = 0;
709 int basicperms = 0;
710
711 /*
712 * If the parent does not have a default ACL, or it's an
713 * invalid ACL, we're done.
714 */
715 if (!vp)
716 return 0;
717 if (!pdaclp || xfs_acl_invalid(pdaclp))
718 return 0;
719
720 /*
721 * Copy the default ACL of the containing directory to
722 * the access ACL of the new file and use the mode that
723 * was passed in to set up the correct initial values for
724 * the u::,g::[m::], and o:: entries. This is what makes
725 * umask() "work" with ACL's.
726 */
727
728 if (!(_ACL_ALLOC(cacl)))
729 return ENOMEM;
730
731 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
732 xfs_acl_filter_mode(vap->va_mode, cacl);
733 xfs_acl_setmode(vp, cacl, &basicperms);
734
735 /*
736 * Set the Default and Access ACL on the file. The mode is already
737 * set on the file, so we don't need to worry about that.
738 *
739 * If the new file is a directory, its default ACL is a copy of
740 * the containing directory's default ACL.
741 */
742 if (VN_ISDIR(vp))
743 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
744 if (!error && !basicperms)
745 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
746 _ACL_FREE(cacl);
747 return error;
748 }
749
750 /*
751 * Set up the correct mode on the file based on the supplied ACL. This
752 * makes sure that the mode on the file reflects the state of the
753 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
754 * the ACL is going to get the permissions for these entries, we must
755 * synchronize the mode whenever we set the ACL on a file.
756 */
757 STATIC int
758 xfs_acl_setmode(
759 vnode_t *vp,
760 xfs_acl_t *acl,
761 int *basicperms)
762 {
763 vattr_t va;
764 xfs_acl_entry_t *ap;
765 xfs_acl_entry_t *gap = NULL;
766 int i, error, nomask = 1;
767
768 *basicperms = 1;
769
770 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
771 return 0;
772
773 /*
774 * Copy the u::, g::, o::, and m:: bits from the ACL into the
775 * mode. The m:: bits take precedence over the g:: bits.
776 */
777 va.va_mask = XFS_AT_MODE;
778 VOP_GETATTR(vp, &va, 0, sys_cred, error);
779 if (error)
780 return error;
781
782 va.va_mask = XFS_AT_MODE;
783 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
784 ap = acl->acl_entry;
785 for (i = 0; i < acl->acl_cnt; ++i) {
786 switch (ap->ae_tag) {
787 case ACL_USER_OBJ:
788 va.va_mode |= ap->ae_perm << 6;
789 break;
790 case ACL_GROUP_OBJ:
791 gap = ap;
792 break;
793 case ACL_MASK: /* more than just standard modes */
794 nomask = 0;
795 va.va_mode |= ap->ae_perm << 3;
796 *basicperms = 0;
797 break;
798 case ACL_OTHER:
799 va.va_mode |= ap->ae_perm;
800 break;
801 default: /* more than just standard modes */
802 *basicperms = 0;
803 break;
804 }
805 ap++;
806 }
807
808 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
809 if (gap && nomask)
810 va.va_mode |= gap->ae_perm << 3;
811
812 VOP_SETATTR(vp, &va, 0, sys_cred, error);
813 return error;
814 }
815
816 /*
817 * The permissions for the special ACL entries (u::, g::[m::], o::) are
818 * actually stored in the file mode (if there is both a group and a mask,
819 * the group is stored in the ACL entry and the mask is stored on the file).
820 * This allows the mode to remain automatically in sync with the ACL without
821 * the need for a call-back to the ACL system at every point where the mode
822 * could change. This function takes the permissions from the specified mode
823 * and places it in the supplied ACL.
824 *
825 * This implementation draws its validity from the fact that, when the ACL
826 * was assigned, the mode was copied from the ACL.
827 * If the mode did not change, therefore, the mode remains exactly what was
828 * taken from the special ACL entries at assignment.
829 * If a subsequent chmod() was done, the POSIX spec says that the change in
830 * mode must cause an update to the ACL seen at user level and used for
831 * access checks. Before and after a mode change, therefore, the file mode
832 * most accurately reflects what the special ACL entries should permit/deny.
833 *
834 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
835 * the existing mode bits will override whatever is in the
836 * ACL. Similarly, if there is a pre-existing ACL that was
837 * never in sync with its mode (owing to a bug in 6.5 and
838 * before), it will now magically (or mystically) be
839 * synchronized. This could cause slight astonishment, but
840 * it is better than inconsistent permissions.
841 *
842 * The supplied ACL is a template that may contain any combination
843 * of special entries. These are treated as place holders when we fill
844 * out the ACL. This routine does not add or remove special entries, it
845 * simply unites each special entry with its associated set of permissions.
846 */
847 STATIC void
848 xfs_acl_sync_mode(
849 mode_t mode,
850 xfs_acl_t *acl)
851 {
852 int i, nomask = 1;
853 xfs_acl_entry_t *ap;
854 xfs_acl_entry_t *gap = NULL;
855
856 /*
857 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
858 * be set instead of the GROUP entry, if there is a MASK.
859 */
860 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
861 switch (ap->ae_tag) {
862 case ACL_USER_OBJ:
863 ap->ae_perm = (mode >> 6) & 0x7;
864 break;
865 case ACL_GROUP_OBJ:
866 gap = ap;
867 break;
868 case ACL_MASK:
869 nomask = 0;
870 ap->ae_perm = (mode >> 3) & 0x7;
871 break;
872 case ACL_OTHER:
873 ap->ae_perm = mode & 0x7;
874 break;
875 default:
876 break;
877 }
878 }
879 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
880 if (gap && nomask)
881 gap->ae_perm = (mode >> 3) & 0x7;
882 }
883
884 /*
885 * When inheriting an Access ACL from a directory Default ACL,
886 * the ACL bits are set to the intersection of the ACL default
887 * permission bits and the file permission bits in mode. If there
888 * are no permission bits on the file then we must not give them
889 * the ACL. This is what what makes umask() work with ACLs.
890 */
891 STATIC void
892 xfs_acl_filter_mode(
893 mode_t mode,
894 xfs_acl_t *acl)
895 {
896 int i, nomask = 1;
897 xfs_acl_entry_t *ap;
898 xfs_acl_entry_t *gap = NULL;
899
900 /*
901 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
902 * be merged with GROUP entry, if there is a MASK.
903 */
904 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
905 switch (ap->ae_tag) {
906 case ACL_USER_OBJ:
907 ap->ae_perm &= (mode >> 6) & 0x7;
908 break;
909 case ACL_GROUP_OBJ:
910 gap = ap;
911 break;
912 case ACL_MASK:
913 nomask = 0;
914 ap->ae_perm &= (mode >> 3) & 0x7;
915 break;
916 case ACL_OTHER:
917 ap->ae_perm &= mode & 0x7;
918 break;
919 default:
920 break;
921 }
922 }
923 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
924 if (gap && nomask)
925 gap->ae_perm &= (mode >> 3) & 0x7;
926 }
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