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_dir2.h"
25 #include "xfs_bmap_btree.h"
26 #include "xfs_alloc_btree.h"
27 #include "xfs_ialloc_btree.h"
28 #include "xfs_dir2_sf.h"
29 #include "xfs_attr_sf.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_btree.h"
33 #include "xfs_acl.h"
34 #include "xfs_attr.h"
35 #include "xfs_vnodeops.h"
36
37 #include <linux/capability.h>
38 #include <linux/posix_acl_xattr.h>
39
40 STATIC int xfs_acl_setmode(struct inode *, xfs_acl_t *, int *);
41 STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
42 STATIC void xfs_acl_get_endian(xfs_acl_t *);
43 STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
44 STATIC int xfs_acl_invalid(xfs_acl_t *);
45 STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
46 STATIC void xfs_acl_get_attr(struct inode *, xfs_acl_t *, int, int, int *);
47 STATIC void xfs_acl_set_attr(struct inode *, xfs_acl_t *, int, int *);
48 STATIC int xfs_acl_allow_set(struct inode *, int);
49
50 kmem_zone_t *xfs_acl_zone;
51
52
53 /*
54 * Test for existence of access ACL attribute as efficiently as possible.
55 */
56 int
xfs_acl_vhasacl_access(struct inode * vp)57 xfs_acl_vhasacl_access(
58 struct inode *vp)
59 {
60 int error;
61
62 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
63 return (error == 0);
64 }
65
66 /*
67 * Test for existence of default ACL attribute as efficiently as possible.
68 */
69 int
xfs_acl_vhasacl_default(struct inode * vp)70 xfs_acl_vhasacl_default(
71 struct inode *vp)
72 {
73 int error;
74
75 if (!S_ISDIR(vp->i_mode))
76 return 0;
77 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
78 return (error == 0);
79 }
80
81 /*
82 * Convert from extended attribute representation to in-memory for XFS.
83 */
84 STATIC int
posix_acl_xattr_to_xfs(posix_acl_xattr_header * src,size_t size,xfs_acl_t * dest)85 posix_acl_xattr_to_xfs(
86 posix_acl_xattr_header *src,
87 size_t size,
88 xfs_acl_t *dest)
89 {
90 posix_acl_xattr_entry *src_entry;
91 xfs_acl_entry_t *dest_entry;
92 int n;
93
94 if (!src || !dest)
95 return EINVAL;
96
97 if (size < sizeof(posix_acl_xattr_header))
98 return EINVAL;
99
100 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
101 return EOPNOTSUPP;
102
103 memset(dest, 0, sizeof(xfs_acl_t));
104 dest->acl_cnt = posix_acl_xattr_count(size);
105 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
106 return EINVAL;
107
108 /*
109 * acl_set_file(3) may request that we set default ACLs with
110 * zero length -- defend (gracefully) against that here.
111 */
112 if (!dest->acl_cnt)
113 return 0;
114
115 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
116 dest_entry = &dest->acl_entry[0];
117
118 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
119 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
120 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
121 return EINVAL;
122 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
123 switch(dest_entry->ae_tag) {
124 case ACL_USER:
125 case ACL_GROUP:
126 dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
127 break;
128 case ACL_USER_OBJ:
129 case ACL_GROUP_OBJ:
130 case ACL_MASK:
131 case ACL_OTHER:
132 dest_entry->ae_id = ACL_UNDEFINED_ID;
133 break;
134 default:
135 return EINVAL;
136 }
137 }
138 if (xfs_acl_invalid(dest))
139 return EINVAL;
140
141 return 0;
142 }
143
144 /*
145 * Comparison function called from xfs_sort().
146 * Primary key is ae_tag, secondary key is ae_id.
147 */
148 STATIC int
xfs_acl_entry_compare(const void * va,const void * vb)149 xfs_acl_entry_compare(
150 const void *va,
151 const void *vb)
152 {
153 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
154 *b = (xfs_acl_entry_t *)vb;
155
156 if (a->ae_tag == b->ae_tag)
157 return (a->ae_id - b->ae_id);
158 return (a->ae_tag - b->ae_tag);
159 }
160
161 /*
162 * Convert from in-memory XFS to extended attribute representation.
163 */
164 STATIC int
posix_acl_xfs_to_xattr(xfs_acl_t * src,posix_acl_xattr_header * dest,size_t size)165 posix_acl_xfs_to_xattr(
166 xfs_acl_t *src,
167 posix_acl_xattr_header *dest,
168 size_t size)
169 {
170 int n;
171 size_t new_size = posix_acl_xattr_size(src->acl_cnt);
172 posix_acl_xattr_entry *dest_entry;
173 xfs_acl_entry_t *src_entry;
174
175 if (size < new_size)
176 return -ERANGE;
177
178 /* Need to sort src XFS ACL by <ae_tag,ae_id> */
179 xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
180 xfs_acl_entry_compare);
181
182 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
183 dest_entry = &dest->a_entries[0];
184 src_entry = &src->acl_entry[0];
185 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
186 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
187 if (_ACL_PERM_INVALID(src_entry->ae_perm))
188 return -EINVAL;
189 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
190 switch (src_entry->ae_tag) {
191 case ACL_USER:
192 case ACL_GROUP:
193 dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
194 break;
195 case ACL_USER_OBJ:
196 case ACL_GROUP_OBJ:
197 case ACL_MASK:
198 case ACL_OTHER:
199 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
200 break;
201 default:
202 return -EINVAL;
203 }
204 }
205 return new_size;
206 }
207
208 int
xfs_acl_vget(struct inode * vp,void * acl,size_t size,int kind)209 xfs_acl_vget(
210 struct inode *vp,
211 void *acl,
212 size_t size,
213 int kind)
214 {
215 int error;
216 xfs_acl_t *xfs_acl = NULL;
217 posix_acl_xattr_header *ext_acl = acl;
218 int flags = 0;
219
220 if(size) {
221 if (!(_ACL_ALLOC(xfs_acl))) {
222 error = ENOMEM;
223 goto out;
224 }
225 memset(xfs_acl, 0, sizeof(xfs_acl_t));
226 } else
227 flags = ATTR_KERNOVAL;
228
229 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
230 if (error)
231 goto out;
232
233 if (!size) {
234 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
235 } else {
236 if (xfs_acl_invalid(xfs_acl)) {
237 error = EINVAL;
238 goto out;
239 }
240 if (kind == _ACL_TYPE_ACCESS)
241 xfs_acl_sync_mode(XFS_I(vp)->i_d.di_mode, xfs_acl);
242 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
243 }
244 out:
245 if(xfs_acl)
246 _ACL_FREE(xfs_acl);
247 return -error;
248 }
249
250 int
xfs_acl_vremove(struct inode * vp,int kind)251 xfs_acl_vremove(
252 struct inode *vp,
253 int kind)
254 {
255 int error;
256
257 error = xfs_acl_allow_set(vp, kind);
258 if (!error) {
259 error = xfs_attr_remove(XFS_I(vp),
260 kind == _ACL_TYPE_DEFAULT?
261 SGI_ACL_DEFAULT: SGI_ACL_FILE,
262 ATTR_ROOT);
263 if (error == ENOATTR)
264 error = 0; /* 'scool */
265 }
266 return -error;
267 }
268
269 int
xfs_acl_vset(struct inode * vp,void * acl,size_t size,int kind)270 xfs_acl_vset(
271 struct inode *vp,
272 void *acl,
273 size_t size,
274 int kind)
275 {
276 posix_acl_xattr_header *ext_acl = acl;
277 xfs_acl_t *xfs_acl;
278 int error;
279 int basicperms = 0; /* more than std unix perms? */
280
281 if (!acl)
282 return -EINVAL;
283
284 if (!(_ACL_ALLOC(xfs_acl)))
285 return -ENOMEM;
286
287 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
288 if (error) {
289 _ACL_FREE(xfs_acl);
290 return -error;
291 }
292 if (!xfs_acl->acl_cnt) {
293 _ACL_FREE(xfs_acl);
294 return 0;
295 }
296
297 error = xfs_acl_allow_set(vp, kind);
298
299 /* Incoming ACL exists, set file mode based on its value */
300 if (!error && kind == _ACL_TYPE_ACCESS)
301 error = xfs_acl_setmode(vp, xfs_acl, &basicperms);
302
303 if (error)
304 goto out;
305
306 /*
307 * If we have more than std unix permissions, set up the actual attr.
308 * Otherwise, delete any existing attr. This prevents us from
309 * having actual attrs for permissions that can be stored in the
310 * standard permission bits.
311 */
312 if (!basicperms) {
313 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
314 } else {
315 error = -xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
316 }
317
318 out:
319 _ACL_FREE(xfs_acl);
320 return -error;
321 }
322
323 int
xfs_acl_iaccess(xfs_inode_t * ip,mode_t mode,cred_t * cr)324 xfs_acl_iaccess(
325 xfs_inode_t *ip,
326 mode_t mode,
327 cred_t *cr)
328 {
329 xfs_acl_t *acl;
330 int rval;
331 struct xfs_name acl_name = {SGI_ACL_FILE, SGI_ACL_FILE_SIZE};
332
333 if (!(_ACL_ALLOC(acl)))
334 return -1;
335
336 /* If the file has no ACL return -1. */
337 rval = sizeof(xfs_acl_t);
338 if (xfs_attr_fetch(ip, &acl_name, (char *)acl, &rval, ATTR_ROOT)) {
339 _ACL_FREE(acl);
340 return -1;
341 }
342 xfs_acl_get_endian(acl);
343
344 /* If the file has an empty ACL return -1. */
345 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
346 _ACL_FREE(acl);
347 return -1;
348 }
349
350 /* Synchronize ACL with mode bits */
351 xfs_acl_sync_mode(ip->i_d.di_mode, acl);
352
353 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
354 _ACL_FREE(acl);
355 return rval;
356 }
357
358 STATIC int
xfs_acl_allow_set(struct inode * vp,int kind)359 xfs_acl_allow_set(
360 struct inode *vp,
361 int kind)
362 {
363 if (vp->i_flags & (S_IMMUTABLE|S_APPEND))
364 return EPERM;
365 if (kind == _ACL_TYPE_DEFAULT && !S_ISDIR(vp->i_mode))
366 return ENOTDIR;
367 if (vp->i_sb->s_flags & MS_RDONLY)
368 return EROFS;
369 if (XFS_I(vp)->i_d.di_uid != current_fsuid() && !capable(CAP_FOWNER))
370 return EPERM;
371 return 0;
372 }
373
374 /*
375 * Note: cr is only used here for the capability check if the ACL test fails.
376 * It is not used to find out the credentials uid or groups etc, as was
377 * done in IRIX. It is assumed that the uid and groups for the current
378 * thread are taken from "current" instead of the cr parameter.
379 */
380 STATIC int
xfs_acl_access(uid_t fuid,gid_t fgid,xfs_acl_t * fap,mode_t md,cred_t * cr)381 xfs_acl_access(
382 uid_t fuid,
383 gid_t fgid,
384 xfs_acl_t *fap,
385 mode_t md,
386 cred_t *cr)
387 {
388 xfs_acl_entry_t matched;
389 int i, allows;
390 int maskallows = -1; /* true, but not 1, either */
391 int seen_userobj = 0;
392
393 matched.ae_tag = 0; /* Invalid type */
394 matched.ae_perm = 0;
395
396 for (i = 0; i < fap->acl_cnt; i++) {
397 /*
398 * Break out if we've got a user_obj entry or
399 * a user entry and the mask (and have processed USER_OBJ)
400 */
401 if (matched.ae_tag == ACL_USER_OBJ)
402 break;
403 if (matched.ae_tag == ACL_USER) {
404 if (maskallows != -1 && seen_userobj)
405 break;
406 if (fap->acl_entry[i].ae_tag != ACL_MASK &&
407 fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
408 continue;
409 }
410 /* True if this entry allows the requested access */
411 allows = ((fap->acl_entry[i].ae_perm & md) == md);
412
413 switch (fap->acl_entry[i].ae_tag) {
414 case ACL_USER_OBJ:
415 seen_userobj = 1;
416 if (fuid != current_fsuid())
417 continue;
418 matched.ae_tag = ACL_USER_OBJ;
419 matched.ae_perm = allows;
420 break;
421 case ACL_USER:
422 if (fap->acl_entry[i].ae_id != current_fsuid())
423 continue;
424 matched.ae_tag = ACL_USER;
425 matched.ae_perm = allows;
426 break;
427 case ACL_GROUP_OBJ:
428 if ((matched.ae_tag == ACL_GROUP_OBJ ||
429 matched.ae_tag == ACL_GROUP) && !allows)
430 continue;
431 if (!in_group_p(fgid))
432 continue;
433 matched.ae_tag = ACL_GROUP_OBJ;
434 matched.ae_perm = allows;
435 break;
436 case ACL_GROUP:
437 if ((matched.ae_tag == ACL_GROUP_OBJ ||
438 matched.ae_tag == ACL_GROUP) && !allows)
439 continue;
440 if (!in_group_p(fap->acl_entry[i].ae_id))
441 continue;
442 matched.ae_tag = ACL_GROUP;
443 matched.ae_perm = allows;
444 break;
445 case ACL_MASK:
446 maskallows = allows;
447 break;
448 case ACL_OTHER:
449 if (matched.ae_tag != 0)
450 continue;
451 matched.ae_tag = ACL_OTHER;
452 matched.ae_perm = allows;
453 break;
454 }
455 }
456 /*
457 * First possibility is that no matched entry allows access.
458 * The capability to override DAC may exist, so check for it.
459 */
460 switch (matched.ae_tag) {
461 case ACL_OTHER:
462 case ACL_USER_OBJ:
463 if (matched.ae_perm)
464 return 0;
465 break;
466 case ACL_USER:
467 case ACL_GROUP_OBJ:
468 case ACL_GROUP:
469 if (maskallows && matched.ae_perm)
470 return 0;
471 break;
472 case 0:
473 break;
474 }
475
476 /* EACCES tells generic_permission to check for capability overrides */
477 return EACCES;
478 }
479
480 /*
481 * ACL validity checker.
482 * This acl validation routine checks each ACL entry read in makes sense.
483 */
484 STATIC int
xfs_acl_invalid(xfs_acl_t * aclp)485 xfs_acl_invalid(
486 xfs_acl_t *aclp)
487 {
488 xfs_acl_entry_t *entry, *e;
489 int user = 0, group = 0, other = 0, mask = 0;
490 int mask_required = 0;
491 int i, j;
492
493 if (!aclp)
494 goto acl_invalid;
495
496 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
497 goto acl_invalid;
498
499 for (i = 0; i < aclp->acl_cnt; i++) {
500 entry = &aclp->acl_entry[i];
501 switch (entry->ae_tag) {
502 case ACL_USER_OBJ:
503 if (user++)
504 goto acl_invalid;
505 break;
506 case ACL_GROUP_OBJ:
507 if (group++)
508 goto acl_invalid;
509 break;
510 case ACL_OTHER:
511 if (other++)
512 goto acl_invalid;
513 break;
514 case ACL_USER:
515 case ACL_GROUP:
516 for (j = i + 1; j < aclp->acl_cnt; j++) {
517 e = &aclp->acl_entry[j];
518 if (e->ae_id == entry->ae_id &&
519 e->ae_tag == entry->ae_tag)
520 goto acl_invalid;
521 }
522 mask_required++;
523 break;
524 case ACL_MASK:
525 if (mask++)
526 goto acl_invalid;
527 break;
528 default:
529 goto acl_invalid;
530 }
531 }
532 if (!user || !group || !other || (mask_required && !mask))
533 goto acl_invalid;
534 else
535 return 0;
536 acl_invalid:
537 return EINVAL;
538 }
539
540 /*
541 * Do ACL endian conversion.
542 */
543 STATIC void
xfs_acl_get_endian(xfs_acl_t * aclp)544 xfs_acl_get_endian(
545 xfs_acl_t *aclp)
546 {
547 xfs_acl_entry_t *ace, *end;
548
549 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
550 end = &aclp->acl_entry[0]+aclp->acl_cnt;
551 for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
552 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
553 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
554 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
555 }
556 }
557
558 /*
559 * Get the ACL from the EA and do endian conversion.
560 */
561 STATIC void
xfs_acl_get_attr(struct inode * vp,xfs_acl_t * aclp,int kind,int flags,int * error)562 xfs_acl_get_attr(
563 struct inode *vp,
564 xfs_acl_t *aclp,
565 int kind,
566 int flags,
567 int *error)
568 {
569 int len = sizeof(xfs_acl_t);
570
571 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
572 flags |= ATTR_ROOT;
573 *error = xfs_attr_get(XFS_I(vp),
574 kind == _ACL_TYPE_ACCESS ?
575 SGI_ACL_FILE : SGI_ACL_DEFAULT,
576 (char *)aclp, &len, flags);
577 if (*error || (flags & ATTR_KERNOVAL))
578 return;
579 xfs_acl_get_endian(aclp);
580 }
581
582 /*
583 * Set the EA with the ACL and do endian conversion.
584 */
585 STATIC void
xfs_acl_set_attr(struct inode * vp,xfs_acl_t * aclp,int kind,int * error)586 xfs_acl_set_attr(
587 struct inode *vp,
588 xfs_acl_t *aclp,
589 int kind,
590 int *error)
591 {
592 xfs_acl_entry_t *ace, *newace, *end;
593 xfs_acl_t *newacl;
594 int len;
595
596 if (!(_ACL_ALLOC(newacl))) {
597 *error = ENOMEM;
598 return;
599 }
600
601 len = sizeof(xfs_acl_t) -
602 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
603 end = &aclp->acl_entry[0]+aclp->acl_cnt;
604 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
605 ace < end;
606 ace++, newace++) {
607 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
608 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
609 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
610 }
611 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
612 *error = xfs_attr_set(XFS_I(vp),
613 kind == _ACL_TYPE_ACCESS ?
614 SGI_ACL_FILE: SGI_ACL_DEFAULT,
615 (char *)newacl, len, ATTR_ROOT);
616 _ACL_FREE(newacl);
617 }
618
619 int
xfs_acl_vtoacl(struct inode * vp,xfs_acl_t * access_acl,xfs_acl_t * default_acl)620 xfs_acl_vtoacl(
621 struct inode *vp,
622 xfs_acl_t *access_acl,
623 xfs_acl_t *default_acl)
624 {
625 int error = 0;
626
627 if (access_acl) {
628 /*
629 * Get the Access ACL and the mode. If either cannot
630 * be obtained for some reason, invalidate the access ACL.
631 */
632 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
633 if (error)
634 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
635 else /* We have a good ACL and the file mode, synchronize. */
636 xfs_acl_sync_mode(XFS_I(vp)->i_d.di_mode, access_acl);
637 }
638
639 if (default_acl) {
640 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
641 if (error)
642 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
643 }
644 return error;
645 }
646
647 /*
648 * This function retrieves the parent directory's acl, processes it
649 * and lets the child inherit the acl(s) that it should.
650 */
651 int
xfs_acl_inherit(struct inode * vp,mode_t mode,xfs_acl_t * pdaclp)652 xfs_acl_inherit(
653 struct inode *vp,
654 mode_t mode,
655 xfs_acl_t *pdaclp)
656 {
657 xfs_acl_t *cacl;
658 int error = 0;
659 int basicperms = 0;
660
661 /*
662 * If the parent does not have a default ACL, or it's an
663 * invalid ACL, we're done.
664 */
665 if (!vp)
666 return 0;
667 if (!pdaclp || xfs_acl_invalid(pdaclp))
668 return 0;
669
670 /*
671 * Copy the default ACL of the containing directory to
672 * the access ACL of the new file and use the mode that
673 * was passed in to set up the correct initial values for
674 * the u::,g::[m::], and o:: entries. This is what makes
675 * umask() "work" with ACL's.
676 */
677
678 if (!(_ACL_ALLOC(cacl)))
679 return ENOMEM;
680
681 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
682 xfs_acl_filter_mode(mode, cacl);
683 error = xfs_acl_setmode(vp, cacl, &basicperms);
684 if (error)
685 goto out_error;
686
687 /*
688 * Set the Default and Access ACL on the file. The mode is already
689 * set on the file, so we don't need to worry about that.
690 *
691 * If the new file is a directory, its default ACL is a copy of
692 * the containing directory's default ACL.
693 */
694 if (S_ISDIR(vp->i_mode))
695 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
696 if (!error && !basicperms)
697 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
698 out_error:
699 _ACL_FREE(cacl);
700 return error;
701 }
702
703 /*
704 * Set up the correct mode on the file based on the supplied ACL. This
705 * makes sure that the mode on the file reflects the state of the
706 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
707 * the ACL is going to get the permissions for these entries, we must
708 * synchronize the mode whenever we set the ACL on a file.
709 */
710 STATIC int
xfs_acl_setmode(struct inode * vp,xfs_acl_t * acl,int * basicperms)711 xfs_acl_setmode(
712 struct inode *vp,
713 xfs_acl_t *acl,
714 int *basicperms)
715 {
716 struct iattr iattr;
717 xfs_acl_entry_t *ap;
718 xfs_acl_entry_t *gap = NULL;
719 int i, nomask = 1;
720
721 *basicperms = 1;
722
723 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
724 return 0;
725
726 /*
727 * Copy the u::, g::, o::, and m:: bits from the ACL into the
728 * mode. The m:: bits take precedence over the g:: bits.
729 */
730 iattr.ia_valid = ATTR_MODE;
731 iattr.ia_mode = XFS_I(vp)->i_d.di_mode;
732 iattr.ia_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
733 ap = acl->acl_entry;
734 for (i = 0; i < acl->acl_cnt; ++i) {
735 switch (ap->ae_tag) {
736 case ACL_USER_OBJ:
737 iattr.ia_mode |= ap->ae_perm << 6;
738 break;
739 case ACL_GROUP_OBJ:
740 gap = ap;
741 break;
742 case ACL_MASK: /* more than just standard modes */
743 nomask = 0;
744 iattr.ia_mode |= ap->ae_perm << 3;
745 *basicperms = 0;
746 break;
747 case ACL_OTHER:
748 iattr.ia_mode |= ap->ae_perm;
749 break;
750 default: /* more than just standard modes */
751 *basicperms = 0;
752 break;
753 }
754 ap++;
755 }
756
757 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
758 if (gap && nomask)
759 iattr.ia_mode |= gap->ae_perm << 3;
760
761 return xfs_setattr(XFS_I(vp), &iattr, 0);
762 }
763
764 /*
765 * The permissions for the special ACL entries (u::, g::[m::], o::) are
766 * actually stored in the file mode (if there is both a group and a mask,
767 * the group is stored in the ACL entry and the mask is stored on the file).
768 * This allows the mode to remain automatically in sync with the ACL without
769 * the need for a call-back to the ACL system at every point where the mode
770 * could change. This function takes the permissions from the specified mode
771 * and places it in the supplied ACL.
772 *
773 * This implementation draws its validity from the fact that, when the ACL
774 * was assigned, the mode was copied from the ACL.
775 * If the mode did not change, therefore, the mode remains exactly what was
776 * taken from the special ACL entries at assignment.
777 * If a subsequent chmod() was done, the POSIX spec says that the change in
778 * mode must cause an update to the ACL seen at user level and used for
779 * access checks. Before and after a mode change, therefore, the file mode
780 * most accurately reflects what the special ACL entries should permit/deny.
781 *
782 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
783 * the existing mode bits will override whatever is in the
784 * ACL. Similarly, if there is a pre-existing ACL that was
785 * never in sync with its mode (owing to a bug in 6.5 and
786 * before), it will now magically (or mystically) be
787 * synchronized. This could cause slight astonishment, but
788 * it is better than inconsistent permissions.
789 *
790 * The supplied ACL is a template that may contain any combination
791 * of special entries. These are treated as place holders when we fill
792 * out the ACL. This routine does not add or remove special entries, it
793 * simply unites each special entry with its associated set of permissions.
794 */
795 STATIC void
xfs_acl_sync_mode(mode_t mode,xfs_acl_t * acl)796 xfs_acl_sync_mode(
797 mode_t mode,
798 xfs_acl_t *acl)
799 {
800 int i, nomask = 1;
801 xfs_acl_entry_t *ap;
802 xfs_acl_entry_t *gap = NULL;
803
804 /*
805 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
806 * be set instead of the GROUP entry, if there is a MASK.
807 */
808 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
809 switch (ap->ae_tag) {
810 case ACL_USER_OBJ:
811 ap->ae_perm = (mode >> 6) & 0x7;
812 break;
813 case ACL_GROUP_OBJ:
814 gap = ap;
815 break;
816 case ACL_MASK:
817 nomask = 0;
818 ap->ae_perm = (mode >> 3) & 0x7;
819 break;
820 case ACL_OTHER:
821 ap->ae_perm = mode & 0x7;
822 break;
823 default:
824 break;
825 }
826 }
827 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
828 if (gap && nomask)
829 gap->ae_perm = (mode >> 3) & 0x7;
830 }
831
832 /*
833 * When inheriting an Access ACL from a directory Default ACL,
834 * the ACL bits are set to the intersection of the ACL default
835 * permission bits and the file permission bits in mode. If there
836 * are no permission bits on the file then we must not give them
837 * the ACL. This is what what makes umask() work with ACLs.
838 */
839 STATIC void
xfs_acl_filter_mode(mode_t mode,xfs_acl_t * acl)840 xfs_acl_filter_mode(
841 mode_t mode,
842 xfs_acl_t *acl)
843 {
844 int i, nomask = 1;
845 xfs_acl_entry_t *ap;
846 xfs_acl_entry_t *gap = NULL;
847
848 /*
849 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
850 * be merged with GROUP entry, if there is a MASK.
851 */
852 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
853 switch (ap->ae_tag) {
854 case ACL_USER_OBJ:
855 ap->ae_perm &= (mode >> 6) & 0x7;
856 break;
857 case ACL_GROUP_OBJ:
858 gap = ap;
859 break;
860 case ACL_MASK:
861 nomask = 0;
862 ap->ae_perm &= (mode >> 3) & 0x7;
863 break;
864 case ACL_OTHER:
865 ap->ae_perm &= mode & 0x7;
866 break;
867 default:
868 break;
869 }
870 }
871 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
872 if (gap && nomask)
873 gap->ae_perm &= (mode >> 3) & 0x7;
874 }
875