blob: 4ff0f4e41c6132227bba56c7565379aca0d90c5b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2001-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include "xfs.h"
Nathan Scotta844f452005-11-02 14:38:42 +110019#include "xfs_fs.h"
20#include "xfs_types.h"
21#include "xfs_bit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "xfs_inum.h"
Nathan Scotta844f452005-11-02 14:38:42 +110023#include "xfs_ag.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "xfs_dir.h"
25#include "xfs_dir2.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include "xfs_bmap_btree.h"
Nathan Scotta844f452005-11-02 14:38:42 +110027#include "xfs_alloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include "xfs_ialloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include "xfs_dir_sf.h"
30#include "xfs_dir2_sf.h"
Nathan Scotta844f452005-11-02 14:38:42 +110031#include "xfs_attr_sf.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include "xfs_dinode.h"
33#include "xfs_inode.h"
Nathan Scotta844f452005-11-02 14:38:42 +110034#include "xfs_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include "xfs_acl.h"
36#include "xfs_mac.h"
37#include "xfs_attr.h"
38
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080039#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#include <linux/posix_acl_xattr.h>
41
42STATIC int xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
43STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
44STATIC void xfs_acl_get_endian(xfs_acl_t *);
45STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
46STATIC int xfs_acl_invalid(xfs_acl_t *);
47STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
48STATIC void xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
49STATIC void xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
50STATIC int xfs_acl_allow_set(vnode_t *, int);
51
52kmem_zone_t *xfs_acl_zone;
53
54
55/*
56 * Test for existence of access ACL attribute as efficiently as possible.
57 */
58int
59xfs_acl_vhasacl_access(
60 vnode_t *vp)
61{
62 int error;
63
64 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
65 return (error == 0);
66}
67
68/*
69 * Test for existence of default ACL attribute as efficiently as possible.
70 */
71int
72xfs_acl_vhasacl_default(
73 vnode_t *vp)
74{
75 int error;
76
Christoph Hellwig0432dab2005-09-02 16:46:51 +100077 if (!VN_ISDIR(vp))
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return 0;
79 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
80 return (error == 0);
81}
82
83/*
84 * Convert from extended attribute representation to in-memory for XFS.
85 */
86STATIC int
87posix_acl_xattr_to_xfs(
88 posix_acl_xattr_header *src,
89 size_t size,
90 xfs_acl_t *dest)
91{
92 posix_acl_xattr_entry *src_entry;
93 xfs_acl_entry_t *dest_entry;
94 int n;
95
96 if (!src || !dest)
97 return EINVAL;
98
99 if (size < sizeof(posix_acl_xattr_header))
100 return EINVAL;
101
102 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
103 return EOPNOTSUPP;
104
105 memset(dest, 0, sizeof(xfs_acl_t));
106 dest->acl_cnt = posix_acl_xattr_count(size);
107 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
108 return EINVAL;
109
110 /*
111 * acl_set_file(3) may request that we set default ACLs with
112 * zero length -- defend (gracefully) against that here.
113 */
114 if (!dest->acl_cnt)
115 return 0;
116
117 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
118 dest_entry = &dest->acl_entry[0];
119
120 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
121 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
122 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
123 return EINVAL;
124 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
125 switch(dest_entry->ae_tag) {
126 case ACL_USER:
127 case ACL_GROUP:
128 dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
129 break;
130 case ACL_USER_OBJ:
131 case ACL_GROUP_OBJ:
132 case ACL_MASK:
133 case ACL_OTHER:
134 dest_entry->ae_id = ACL_UNDEFINED_ID;
135 break;
136 default:
137 return EINVAL;
138 }
139 }
140 if (xfs_acl_invalid(dest))
141 return EINVAL;
142
143 return 0;
144}
145
146/*
Nathan Scott380b5dc2005-11-02 11:43:18 +1100147 * Comparison function called from xfs_sort().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 * Primary key is ae_tag, secondary key is ae_id.
149 */
150STATIC int
151xfs_acl_entry_compare(
152 const void *va,
153 const void *vb)
154{
155 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
156 *b = (xfs_acl_entry_t *)vb;
157
158 if (a->ae_tag == b->ae_tag)
159 return (a->ae_id - b->ae_id);
160 return (a->ae_tag - b->ae_tag);
161}
162
163/*
164 * Convert from in-memory XFS to extended attribute representation.
165 */
166STATIC int
167posix_acl_xfs_to_xattr(
168 xfs_acl_t *src,
169 posix_acl_xattr_header *dest,
170 size_t size)
171{
172 int n;
173 size_t new_size = posix_acl_xattr_size(src->acl_cnt);
174 posix_acl_xattr_entry *dest_entry;
175 xfs_acl_entry_t *src_entry;
176
177 if (size < new_size)
178 return -ERANGE;
179
180 /* Need to sort src XFS ACL by <ae_tag,ae_id> */
Nathan Scott380b5dc2005-11-02 11:43:18 +1100181 xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
182 xfs_acl_entry_compare);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
185 dest_entry = &dest->a_entries[0];
186 src_entry = &src->acl_entry[0];
187 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
188 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
189 if (_ACL_PERM_INVALID(src_entry->ae_perm))
190 return -EINVAL;
191 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
192 switch (src_entry->ae_tag) {
193 case ACL_USER:
194 case ACL_GROUP:
195 dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
196 break;
197 case ACL_USER_OBJ:
198 case ACL_GROUP_OBJ:
199 case ACL_MASK:
200 case ACL_OTHER:
201 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
202 break;
203 default:
204 return -EINVAL;
205 }
206 }
207 return new_size;
208}
209
210int
211xfs_acl_vget(
212 vnode_t *vp,
213 void *acl,
214 size_t size,
215 int kind)
216{
217 int error;
218 xfs_acl_t *xfs_acl = NULL;
219 posix_acl_xattr_header *ext_acl = acl;
220 int flags = 0;
221
222 VN_HOLD(vp);
223 if(size) {
224 if (!(_ACL_ALLOC(xfs_acl))) {
225 error = ENOMEM;
226 goto out;
227 }
228 memset(xfs_acl, 0, sizeof(xfs_acl_t));
229 } else
230 flags = ATTR_KERNOVAL;
231
232 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
233 if (error)
234 goto out;
235
236 if (!size) {
237 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
238 } else {
239 if (xfs_acl_invalid(xfs_acl)) {
240 error = EINVAL;
241 goto out;
242 }
243 if (kind == _ACL_TYPE_ACCESS) {
244 vattr_t va;
245
246 va.va_mask = XFS_AT_MODE;
247 VOP_GETATTR(vp, &va, 0, sys_cred, error);
248 if (error)
249 goto out;
250 xfs_acl_sync_mode(va.va_mode, xfs_acl);
251 }
252 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
253 }
254out:
255 VN_RELE(vp);
256 if(xfs_acl)
257 _ACL_FREE(xfs_acl);
258 return -error;
259}
260
261int
262xfs_acl_vremove(
263 vnode_t *vp,
264 int kind)
265{
266 int error;
267
268 VN_HOLD(vp);
269 error = xfs_acl_allow_set(vp, kind);
270 if (!error) {
271 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
272 SGI_ACL_DEFAULT: SGI_ACL_FILE,
273 ATTR_ROOT, sys_cred, error);
274 if (error == ENOATTR)
275 error = 0; /* 'scool */
276 }
277 VN_RELE(vp);
278 return -error;
279}
280
281int
282xfs_acl_vset(
283 vnode_t *vp,
284 void *acl,
285 size_t size,
286 int kind)
287{
288 posix_acl_xattr_header *ext_acl = acl;
289 xfs_acl_t *xfs_acl;
290 int error;
291 int basicperms = 0; /* more than std unix perms? */
292
293 if (!acl)
294 return -EINVAL;
295
296 if (!(_ACL_ALLOC(xfs_acl)))
297 return -ENOMEM;
298
299 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
300 if (error) {
301 _ACL_FREE(xfs_acl);
302 return -error;
303 }
304 if (!xfs_acl->acl_cnt) {
305 _ACL_FREE(xfs_acl);
306 return 0;
307 }
308
309 VN_HOLD(vp);
310 error = xfs_acl_allow_set(vp, kind);
311 if (error)
312 goto out;
313
314 /* Incoming ACL exists, set file mode based on its value */
315 if (kind == _ACL_TYPE_ACCESS)
316 xfs_acl_setmode(vp, xfs_acl, &basicperms);
317
318 /*
319 * If we have more than std unix permissions, set up the actual attr.
320 * Otherwise, delete any existing attr. This prevents us from
321 * having actual attrs for permissions that can be stored in the
322 * standard permission bits.
323 */
324 if (!basicperms) {
325 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
326 } else {
327 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
328 }
329
330out:
331 VN_RELE(vp);
332 _ACL_FREE(xfs_acl);
333 return -error;
334}
335
336int
337xfs_acl_iaccess(
338 xfs_inode_t *ip,
339 mode_t mode,
340 cred_t *cr)
341{
342 xfs_acl_t *acl;
343 int rval;
344
345 if (!(_ACL_ALLOC(acl)))
346 return -1;
347
348 /* If the file has no ACL return -1. */
349 rval = sizeof(xfs_acl_t);
350 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
351 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
352 _ACL_FREE(acl);
353 return -1;
354 }
355 xfs_acl_get_endian(acl);
356
357 /* If the file has an empty ACL return -1. */
358 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
359 _ACL_FREE(acl);
360 return -1;
361 }
362
363 /* Synchronize ACL with mode bits */
364 xfs_acl_sync_mode(ip->i_d.di_mode, acl);
365
366 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
367 _ACL_FREE(acl);
368 return rval;
369}
370
371STATIC int
372xfs_acl_allow_set(
373 vnode_t *vp,
374 int kind)
375{
376 vattr_t va;
377 int error;
378
379 if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
380 return EPERM;
Christoph Hellwig0432dab2005-09-02 16:46:51 +1000381 if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 return ENOTDIR;
383 if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
384 return EROFS;
385 va.va_mask = XFS_AT_UID;
386 VOP_GETATTR(vp, &va, 0, NULL, error);
387 if (error)
388 return error;
389 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
390 return EPERM;
391 return error;
392}
393
394/*
395 * The access control process to determine the access permission:
396 * if uid == file owner id, use the file owner bits.
397 * if gid == file owner group id, use the file group bits.
398 * scan ACL for a maching user or group, and use matched entry
399 * permission. Use total permissions of all matching group entries,
400 * until all acl entries are exhausted. The final permission produced
401 * by matching acl entry or entries needs to be & with group permission.
402 * if not owner, owning group, or matching entry in ACL, use file
403 * other bits.
404 */
405STATIC int
406xfs_acl_capability_check(
407 mode_t mode,
408 cred_t *cr)
409{
410 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
411 return EACCES;
412 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
413 return EACCES;
414 if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
415 return EACCES;
416
417 return 0;
418}
419
420/*
421 * Note: cr is only used here for the capability check if the ACL test fails.
422 * It is not used to find out the credentials uid or groups etc, as was
423 * done in IRIX. It is assumed that the uid and groups for the current
424 * thread are taken from "current" instead of the cr parameter.
425 */
426STATIC int
427xfs_acl_access(
428 uid_t fuid,
429 gid_t fgid,
430 xfs_acl_t *fap,
431 mode_t md,
432 cred_t *cr)
433{
434 xfs_acl_entry_t matched;
435 int i, allows;
436 int maskallows = -1; /* true, but not 1, either */
437 int seen_userobj = 0;
438
439 matched.ae_tag = 0; /* Invalid type */
Christoph Hellwig5bde1ba92005-11-02 15:06:18 +1100440 matched.ae_perm = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 md >>= 6; /* Normalize the bits for comparison */
442
443 for (i = 0; i < fap->acl_cnt; i++) {
444 /*
445 * Break out if we've got a user_obj entry or
446 * a user entry and the mask (and have processed USER_OBJ)
447 */
448 if (matched.ae_tag == ACL_USER_OBJ)
449 break;
450 if (matched.ae_tag == ACL_USER) {
451 if (maskallows != -1 && seen_userobj)
452 break;
453 if (fap->acl_entry[i].ae_tag != ACL_MASK &&
454 fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
455 continue;
456 }
457 /* True if this entry allows the requested access */
458 allows = ((fap->acl_entry[i].ae_perm & md) == md);
459
460 switch (fap->acl_entry[i].ae_tag) {
461 case ACL_USER_OBJ:
462 seen_userobj = 1;
463 if (fuid != current->fsuid)
464 continue;
465 matched.ae_tag = ACL_USER_OBJ;
466 matched.ae_perm = allows;
467 break;
468 case ACL_USER:
469 if (fap->acl_entry[i].ae_id != current->fsuid)
470 continue;
471 matched.ae_tag = ACL_USER;
472 matched.ae_perm = allows;
473 break;
474 case ACL_GROUP_OBJ:
475 if ((matched.ae_tag == ACL_GROUP_OBJ ||
476 matched.ae_tag == ACL_GROUP) && !allows)
477 continue;
478 if (!in_group_p(fgid))
479 continue;
480 matched.ae_tag = ACL_GROUP_OBJ;
481 matched.ae_perm = allows;
482 break;
483 case ACL_GROUP:
484 if ((matched.ae_tag == ACL_GROUP_OBJ ||
485 matched.ae_tag == ACL_GROUP) && !allows)
486 continue;
487 if (!in_group_p(fap->acl_entry[i].ae_id))
488 continue;
489 matched.ae_tag = ACL_GROUP;
490 matched.ae_perm = allows;
491 break;
492 case ACL_MASK:
493 maskallows = allows;
494 break;
495 case ACL_OTHER:
496 if (matched.ae_tag != 0)
497 continue;
498 matched.ae_tag = ACL_OTHER;
499 matched.ae_perm = allows;
500 break;
501 }
502 }
503 /*
504 * First possibility is that no matched entry allows access.
505 * The capability to override DAC may exist, so check for it.
506 */
507 switch (matched.ae_tag) {
508 case ACL_OTHER:
509 case ACL_USER_OBJ:
510 if (matched.ae_perm)
511 return 0;
512 break;
513 case ACL_USER:
514 case ACL_GROUP_OBJ:
515 case ACL_GROUP:
516 if (maskallows && matched.ae_perm)
517 return 0;
518 break;
519 case 0:
520 break;
521 }
522
523 return xfs_acl_capability_check(md, cr);
524}
525
526/*
527 * ACL validity checker.
528 * This acl validation routine checks each ACL entry read in makes sense.
529 */
530STATIC int
531xfs_acl_invalid(
532 xfs_acl_t *aclp)
533{
534 xfs_acl_entry_t *entry, *e;
535 int user = 0, group = 0, other = 0, mask = 0;
536 int mask_required = 0;
537 int i, j;
538
539 if (!aclp)
540 goto acl_invalid;
541
542 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
543 goto acl_invalid;
544
545 for (i = 0; i < aclp->acl_cnt; i++) {
546 entry = &aclp->acl_entry[i];
547 switch (entry->ae_tag) {
548 case ACL_USER_OBJ:
549 if (user++)
550 goto acl_invalid;
551 break;
552 case ACL_GROUP_OBJ:
553 if (group++)
554 goto acl_invalid;
555 break;
556 case ACL_OTHER:
557 if (other++)
558 goto acl_invalid;
559 break;
560 case ACL_USER:
561 case ACL_GROUP:
562 for (j = i + 1; j < aclp->acl_cnt; j++) {
563 e = &aclp->acl_entry[j];
564 if (e->ae_id == entry->ae_id &&
565 e->ae_tag == entry->ae_tag)
566 goto acl_invalid;
567 }
568 mask_required++;
569 break;
570 case ACL_MASK:
571 if (mask++)
572 goto acl_invalid;
573 break;
574 default:
575 goto acl_invalid;
576 }
577 }
578 if (!user || !group || !other || (mask_required && !mask))
579 goto acl_invalid;
580 else
581 return 0;
582acl_invalid:
583 return EINVAL;
584}
585
586/*
587 * Do ACL endian conversion.
588 */
589STATIC void
590xfs_acl_get_endian(
591 xfs_acl_t *aclp)
592{
593 xfs_acl_entry_t *ace, *end;
594
595 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
596 end = &aclp->acl_entry[0]+aclp->acl_cnt;
597 for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
598 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
599 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
600 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
601 }
602}
603
604/*
605 * Get the ACL from the EA and do endian conversion.
606 */
607STATIC void
608xfs_acl_get_attr(
609 vnode_t *vp,
610 xfs_acl_t *aclp,
611 int kind,
612 int flags,
613 int *error)
614{
615 int len = sizeof(xfs_acl_t);
616
617 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
618 flags |= ATTR_ROOT;
619 VOP_ATTR_GET(vp,
620 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
621 (char *)aclp, &len, flags, sys_cred, *error);
622 if (*error || (flags & ATTR_KERNOVAL))
623 return;
624 xfs_acl_get_endian(aclp);
625}
626
627/*
628 * Set the EA with the ACL and do endian conversion.
629 */
630STATIC void
631xfs_acl_set_attr(
632 vnode_t *vp,
633 xfs_acl_t *aclp,
634 int kind,
635 int *error)
636{
637 xfs_acl_entry_t *ace, *newace, *end;
638 xfs_acl_t *newacl;
639 int len;
640
641 if (!(_ACL_ALLOC(newacl))) {
642 *error = ENOMEM;
643 return;
644 }
645
646 len = sizeof(xfs_acl_t) -
647 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
648 end = &aclp->acl_entry[0]+aclp->acl_cnt;
649 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
650 ace < end;
651 ace++, newace++) {
652 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
653 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
654 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
655 }
656 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
657 VOP_ATTR_SET(vp,
658 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
659 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
660 _ACL_FREE(newacl);
661}
662
663int
664xfs_acl_vtoacl(
665 vnode_t *vp,
666 xfs_acl_t *access_acl,
667 xfs_acl_t *default_acl)
668{
669 vattr_t va;
670 int error = 0;
671
672 if (access_acl) {
673 /*
674 * Get the Access ACL and the mode. If either cannot
675 * be obtained for some reason, invalidate the access ACL.
676 */
677 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
678 if (!error) {
679 /* Got the ACL, need the mode... */
680 va.va_mask = XFS_AT_MODE;
681 VOP_GETATTR(vp, &va, 0, sys_cred, error);
682 }
683
684 if (error)
685 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
686 else /* We have a good ACL and the file mode, synchronize. */
687 xfs_acl_sync_mode(va.va_mode, access_acl);
688 }
689
690 if (default_acl) {
691 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
692 if (error)
693 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
694 }
695 return error;
696}
697
698/*
699 * This function retrieves the parent directory's acl, processes it
700 * and lets the child inherit the acl(s) that it should.
701 */
702int
703xfs_acl_inherit(
704 vnode_t *vp,
705 vattr_t *vap,
706 xfs_acl_t *pdaclp)
707{
708 xfs_acl_t *cacl;
709 int error = 0;
710 int basicperms = 0;
711
712 /*
713 * If the parent does not have a default ACL, or it's an
714 * invalid ACL, we're done.
715 */
716 if (!vp)
717 return 0;
718 if (!pdaclp || xfs_acl_invalid(pdaclp))
719 return 0;
720
721 /*
722 * Copy the default ACL of the containing directory to
723 * the access ACL of the new file and use the mode that
724 * was passed in to set up the correct initial values for
725 * the u::,g::[m::], and o:: entries. This is what makes
726 * umask() "work" with ACL's.
727 */
728
729 if (!(_ACL_ALLOC(cacl)))
730 return ENOMEM;
731
732 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
733 xfs_acl_filter_mode(vap->va_mode, cacl);
734 xfs_acl_setmode(vp, cacl, &basicperms);
735
736 /*
737 * Set the Default and Access ACL on the file. The mode is already
738 * set on the file, so we don't need to worry about that.
739 *
740 * If the new file is a directory, its default ACL is a copy of
741 * the containing directory's default ACL.
742 */
Christoph Hellwig0432dab2005-09-02 16:46:51 +1000743 if (VN_ISDIR(vp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
745 if (!error && !basicperms)
746 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
747 _ACL_FREE(cacl);
748 return error;
749}
750
751/*
752 * Set up the correct mode on the file based on the supplied ACL. This
753 * makes sure that the mode on the file reflects the state of the
754 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
755 * the ACL is going to get the permissions for these entries, we must
756 * synchronize the mode whenever we set the ACL on a file.
757 */
758STATIC int
759xfs_acl_setmode(
760 vnode_t *vp,
761 xfs_acl_t *acl,
762 int *basicperms)
763{
764 vattr_t va;
765 xfs_acl_entry_t *ap;
766 xfs_acl_entry_t *gap = NULL;
767 int i, error, nomask = 1;
768
769 *basicperms = 1;
770
771 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
772 return 0;
773
774 /*
775 * Copy the u::, g::, o::, and m:: bits from the ACL into the
776 * mode. The m:: bits take precedence over the g:: bits.
777 */
778 va.va_mask = XFS_AT_MODE;
779 VOP_GETATTR(vp, &va, 0, sys_cred, error);
780 if (error)
781 return error;
782
783 va.va_mask = XFS_AT_MODE;
784 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
785 ap = acl->acl_entry;
786 for (i = 0; i < acl->acl_cnt; ++i) {
787 switch (ap->ae_tag) {
788 case ACL_USER_OBJ:
789 va.va_mode |= ap->ae_perm << 6;
790 break;
791 case ACL_GROUP_OBJ:
792 gap = ap;
793 break;
794 case ACL_MASK: /* more than just standard modes */
795 nomask = 0;
796 va.va_mode |= ap->ae_perm << 3;
797 *basicperms = 0;
798 break;
799 case ACL_OTHER:
800 va.va_mode |= ap->ae_perm;
801 break;
802 default: /* more than just standard modes */
803 *basicperms = 0;
804 break;
805 }
806 ap++;
807 }
808
809 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
810 if (gap && nomask)
811 va.va_mode |= gap->ae_perm << 3;
812
813 VOP_SETATTR(vp, &va, 0, sys_cred, error);
814 return error;
815}
816
817/*
818 * The permissions for the special ACL entries (u::, g::[m::], o::) are
819 * actually stored in the file mode (if there is both a group and a mask,
820 * the group is stored in the ACL entry and the mask is stored on the file).
821 * This allows the mode to remain automatically in sync with the ACL without
822 * the need for a call-back to the ACL system at every point where the mode
823 * could change. This function takes the permissions from the specified mode
824 * and places it in the supplied ACL.
825 *
826 * This implementation draws its validity from the fact that, when the ACL
827 * was assigned, the mode was copied from the ACL.
828 * If the mode did not change, therefore, the mode remains exactly what was
829 * taken from the special ACL entries at assignment.
830 * If a subsequent chmod() was done, the POSIX spec says that the change in
831 * mode must cause an update to the ACL seen at user level and used for
832 * access checks. Before and after a mode change, therefore, the file mode
833 * most accurately reflects what the special ACL entries should permit/deny.
834 *
835 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
836 * the existing mode bits will override whatever is in the
837 * ACL. Similarly, if there is a pre-existing ACL that was
838 * never in sync with its mode (owing to a bug in 6.5 and
839 * before), it will now magically (or mystically) be
840 * synchronized. This could cause slight astonishment, but
841 * it is better than inconsistent permissions.
842 *
843 * The supplied ACL is a template that may contain any combination
844 * of special entries. These are treated as place holders when we fill
845 * out the ACL. This routine does not add or remove special entries, it
846 * simply unites each special entry with its associated set of permissions.
847 */
848STATIC void
849xfs_acl_sync_mode(
850 mode_t mode,
851 xfs_acl_t *acl)
852{
853 int i, nomask = 1;
854 xfs_acl_entry_t *ap;
855 xfs_acl_entry_t *gap = NULL;
856
857 /*
858 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
859 * be set instead of the GROUP entry, if there is a MASK.
860 */
861 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
862 switch (ap->ae_tag) {
863 case ACL_USER_OBJ:
864 ap->ae_perm = (mode >> 6) & 0x7;
865 break;
866 case ACL_GROUP_OBJ:
867 gap = ap;
868 break;
869 case ACL_MASK:
870 nomask = 0;
871 ap->ae_perm = (mode >> 3) & 0x7;
872 break;
873 case ACL_OTHER:
874 ap->ae_perm = mode & 0x7;
875 break;
876 default:
877 break;
878 }
879 }
880 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
881 if (gap && nomask)
882 gap->ae_perm = (mode >> 3) & 0x7;
883}
884
885/*
886 * When inheriting an Access ACL from a directory Default ACL,
887 * the ACL bits are set to the intersection of the ACL default
888 * permission bits and the file permission bits in mode. If there
889 * are no permission bits on the file then we must not give them
890 * the ACL. This is what what makes umask() work with ACLs.
891 */
892STATIC void
893xfs_acl_filter_mode(
894 mode_t mode,
895 xfs_acl_t *acl)
896{
897 int i, nomask = 1;
898 xfs_acl_entry_t *ap;
899 xfs_acl_entry_t *gap = NULL;
900
901 /*
902 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
903 * be merged with GROUP entry, if there is a MASK.
904 */
905 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
906 switch (ap->ae_tag) {
907 case ACL_USER_OBJ:
908 ap->ae_perm &= (mode >> 6) & 0x7;
909 break;
910 case ACL_GROUP_OBJ:
911 gap = ap;
912 break;
913 case ACL_MASK:
914 nomask = 0;
915 ap->ae_perm &= (mode >> 3) & 0x7;
916 break;
917 case ACL_OTHER:
918 ap->ae_perm &= mode & 0x7;
919 break;
920 default:
921 break;
922 }
923 }
924 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
925 if (gap && nomask)
926 gap->ae_perm &= (mode >> 3) & 0x7;
927}