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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_dir2.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include "xfs_bmap_btree.h"
Nathan Scotta844f452005-11-02 14:38:42 +110026#include "xfs_alloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "xfs_ialloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include "xfs_dir2_sf.h"
Nathan Scotta844f452005-11-02 14:38:42 +110029#include "xfs_attr_sf.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include "xfs_dinode.h"
31#include "xfs_inode.h"
Nathan Scotta844f452005-11-02 14:38:42 +110032#include "xfs_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include "xfs_acl.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include "xfs_attr.h"
Christoph Hellwig739bfb22007-08-29 10:58:01 +100035#include "xfs_vnodeops.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080037#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/posix_acl_xattr.h>
39
Nathan Scott67fcaa72006-06-09 17:00:52 +100040STATIC int xfs_acl_setmode(bhv_vnode_t *, xfs_acl_t *, int *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
42STATIC void xfs_acl_get_endian(xfs_acl_t *);
43STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
44STATIC int xfs_acl_invalid(xfs_acl_t *);
45STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
Nathan Scott67fcaa72006-06-09 17:00:52 +100046STATIC void xfs_acl_get_attr(bhv_vnode_t *, xfs_acl_t *, int, int, int *);
47STATIC void xfs_acl_set_attr(bhv_vnode_t *, xfs_acl_t *, int, int *);
48STATIC int xfs_acl_allow_set(bhv_vnode_t *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50kmem_zone_t *xfs_acl_zone;
51
52
53/*
54 * Test for existence of access ACL attribute as efficiently as possible.
55 */
56int
57xfs_acl_vhasacl_access(
Nathan Scott67fcaa72006-06-09 17:00:52 +100058 bhv_vnode_t *vp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
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 */
69int
70xfs_acl_vhasacl_default(
Nathan Scott67fcaa72006-06-09 17:00:52 +100071 bhv_vnode_t *vp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
73 int error;
74
Christoph Hellwig0432dab2005-09-02 16:46:51 +100075 if (!VN_ISDIR(vp))
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 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 */
84STATIC int
85posix_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/*
Nathan Scott380b5dc2005-11-02 11:43:18 +1100145 * Comparison function called from xfs_sort().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 * Primary key is ae_tag, secondary key is ae_id.
147 */
148STATIC int
149xfs_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 */
164STATIC int
165posix_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> */
Nathan Scott380b5dc2005-11-02 11:43:18 +1100179 xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
180 xfs_acl_entry_compare);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
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
208int
209xfs_acl_vget(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000210 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 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 VN_HOLD(vp);
221 if(size) {
222 if (!(_ACL_ALLOC(xfs_acl))) {
223 error = ENOMEM;
224 goto out;
225 }
226 memset(xfs_acl, 0, sizeof(xfs_acl_t));
227 } else
228 flags = ATTR_KERNOVAL;
229
230 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
231 if (error)
232 goto out;
233
234 if (!size) {
235 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
236 } else {
237 if (xfs_acl_invalid(xfs_acl)) {
238 error = EINVAL;
239 goto out;
240 }
241 if (kind == _ACL_TYPE_ACCESS) {
Nathan Scott8285fb52006-06-09 17:07:12 +1000242 bhv_vattr_t va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 va.va_mask = XFS_AT_MODE;
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000245 error = xfs_getattr(xfs_vtoi(vp), &va, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (error)
247 goto out;
248 xfs_acl_sync_mode(va.va_mode, xfs_acl);
249 }
250 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
251 }
252out:
253 VN_RELE(vp);
254 if(xfs_acl)
255 _ACL_FREE(xfs_acl);
256 return -error;
257}
258
259int
260xfs_acl_vremove(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000261 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 int kind)
263{
264 int error;
265
266 VN_HOLD(vp);
267 error = xfs_acl_allow_set(vp, kind);
268 if (!error) {
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000269 error = xfs_attr_remove(xfs_vtoi(vp),
270 kind == _ACL_TYPE_DEFAULT?
Nathan Scott67fcaa72006-06-09 17:00:52 +1000271 SGI_ACL_DEFAULT: SGI_ACL_FILE,
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000272 ATTR_ROOT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 if (error == ENOATTR)
274 error = 0; /* 'scool */
275 }
276 VN_RELE(vp);
277 return -error;
278}
279
280int
281xfs_acl_vset(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000282 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 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
329out:
330 VN_RELE(vp);
331 _ACL_FREE(xfs_acl);
332 return -error;
333}
334
335int
336xfs_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
370STATIC int
371xfs_acl_allow_set(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000372 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 int kind)
374{
Christoph Hellwig2f6f7b32007-08-29 11:44:18 +1000375 xfs_inode_t *ip = xfs_vtoi(vp);
Nathan Scott8285fb52006-06-09 17:07:12 +1000376 bhv_vattr_t va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 int error;
378
Christoph Hellwig0a74cd12007-08-29 11:53:12 +1000379 if (vp->i_flags & (S_IMMUTABLE|S_APPEND))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 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;
Christoph Hellwig0a74cd12007-08-29 11:53:12 +1000383 if (vp->i_sb->s_flags & MS_RDONLY)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 return EROFS;
385 va.va_mask = XFS_AT_UID;
Christoph Hellwig2f6f7b32007-08-29 11:44:18 +1000386 error = xfs_getattr(ip, &va, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 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.
Nathan Scottc41564b2006-03-29 08:55:14 +1000398 * scan ACL for a matching user or group, and use matched entry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 * 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(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000609 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 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;
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000619 *error = xfs_attr_get(xfs_vtoi(vp),
620 kind == _ACL_TYPE_ACCESS ?
Nathan Scott67fcaa72006-06-09 17:00:52 +1000621 SGI_ACL_FILE : SGI_ACL_DEFAULT,
622 (char *)aclp, &len, flags, sys_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 if (*error || (flags & ATTR_KERNOVAL))
624 return;
625 xfs_acl_get_endian(aclp);
626}
627
628/*
629 * Set the EA with the ACL and do endian conversion.
630 */
631STATIC void
632xfs_acl_set_attr(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000633 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 xfs_acl_t *aclp,
635 int kind,
636 int *error)
637{
638 xfs_acl_entry_t *ace, *newace, *end;
639 xfs_acl_t *newacl;
640 int len;
641
642 if (!(_ACL_ALLOC(newacl))) {
643 *error = ENOMEM;
644 return;
645 }
646
647 len = sizeof(xfs_acl_t) -
648 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
649 end = &aclp->acl_entry[0]+aclp->acl_cnt;
650 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
651 ace < end;
652 ace++, newace++) {
653 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
654 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
655 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
656 }
657 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000658 *error = xfs_attr_set(xfs_vtoi(vp),
659 kind == _ACL_TYPE_ACCESS ?
Nathan Scott67fcaa72006-06-09 17:00:52 +1000660 SGI_ACL_FILE: SGI_ACL_DEFAULT,
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000661 (char *)newacl, len, ATTR_ROOT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 _ACL_FREE(newacl);
663}
664
665int
666xfs_acl_vtoacl(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000667 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 xfs_acl_t *access_acl,
669 xfs_acl_t *default_acl)
670{
Nathan Scott8285fb52006-06-09 17:07:12 +1000671 bhv_vattr_t va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 int error = 0;
673
674 if (access_acl) {
675 /*
676 * Get the Access ACL and the mode. If either cannot
677 * be obtained for some reason, invalidate the access ACL.
678 */
679 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
680 if (!error) {
681 /* Got the ACL, need the mode... */
682 va.va_mask = XFS_AT_MODE;
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000683 error = xfs_getattr(xfs_vtoi(vp), &va, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 }
685
686 if (error)
687 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
688 else /* We have a good ACL and the file mode, synchronize. */
689 xfs_acl_sync_mode(va.va_mode, access_acl);
690 }
691
692 if (default_acl) {
693 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
694 if (error)
695 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
696 }
697 return error;
698}
699
700/*
701 * This function retrieves the parent directory's acl, processes it
702 * and lets the child inherit the acl(s) that it should.
703 */
704int
705xfs_acl_inherit(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000706 bhv_vnode_t *vp,
Christoph Hellwig3e5daf02007-10-11 18:09:12 +1000707 mode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 xfs_acl_t *pdaclp)
709{
710 xfs_acl_t *cacl;
711 int error = 0;
712 int basicperms = 0;
713
714 /*
715 * If the parent does not have a default ACL, or it's an
716 * invalid ACL, we're done.
717 */
718 if (!vp)
719 return 0;
720 if (!pdaclp || xfs_acl_invalid(pdaclp))
721 return 0;
722
723 /*
724 * Copy the default ACL of the containing directory to
725 * the access ACL of the new file and use the mode that
726 * was passed in to set up the correct initial values for
727 * the u::,g::[m::], and o:: entries. This is what makes
728 * umask() "work" with ACL's.
729 */
730
731 if (!(_ACL_ALLOC(cacl)))
732 return ENOMEM;
733
734 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
Christoph Hellwig3e5daf02007-10-11 18:09:12 +1000735 xfs_acl_filter_mode(mode, cacl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 xfs_acl_setmode(vp, cacl, &basicperms);
737
738 /*
739 * Set the Default and Access ACL on the file. The mode is already
740 * set on the file, so we don't need to worry about that.
741 *
742 * If the new file is a directory, its default ACL is a copy of
743 * the containing directory's default ACL.
744 */
Christoph Hellwig0432dab2005-09-02 16:46:51 +1000745 if (VN_ISDIR(vp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
747 if (!error && !basicperms)
748 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
749 _ACL_FREE(cacl);
750 return error;
751}
752
753/*
754 * Set up the correct mode on the file based on the supplied ACL. This
755 * makes sure that the mode on the file reflects the state of the
756 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
757 * the ACL is going to get the permissions for these entries, we must
758 * synchronize the mode whenever we set the ACL on a file.
759 */
760STATIC int
761xfs_acl_setmode(
Nathan Scott67fcaa72006-06-09 17:00:52 +1000762 bhv_vnode_t *vp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 xfs_acl_t *acl,
764 int *basicperms)
765{
Nathan Scott8285fb52006-06-09 17:07:12 +1000766 bhv_vattr_t va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 xfs_acl_entry_t *ap;
768 xfs_acl_entry_t *gap = NULL;
769 int i, error, nomask = 1;
770
771 *basicperms = 1;
772
773 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
774 return 0;
775
776 /*
777 * Copy the u::, g::, o::, and m:: bits from the ACL into the
778 * mode. The m:: bits take precedence over the g:: bits.
779 */
780 va.va_mask = XFS_AT_MODE;
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000781 error = xfs_getattr(xfs_vtoi(vp), &va, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 if (error)
783 return error;
784
785 va.va_mask = XFS_AT_MODE;
786 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
787 ap = acl->acl_entry;
788 for (i = 0; i < acl->acl_cnt; ++i) {
789 switch (ap->ae_tag) {
790 case ACL_USER_OBJ:
791 va.va_mode |= ap->ae_perm << 6;
792 break;
793 case ACL_GROUP_OBJ:
794 gap = ap;
795 break;
796 case ACL_MASK: /* more than just standard modes */
797 nomask = 0;
798 va.va_mode |= ap->ae_perm << 3;
799 *basicperms = 0;
800 break;
801 case ACL_OTHER:
802 va.va_mode |= ap->ae_perm;
803 break;
804 default: /* more than just standard modes */
805 *basicperms = 0;
806 break;
807 }
808 ap++;
809 }
810
811 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
812 if (gap && nomask)
813 va.va_mode |= gap->ae_perm << 3;
814
Christoph Hellwig739bfb22007-08-29 10:58:01 +1000815 return xfs_setattr(xfs_vtoi(vp), &va, 0, sys_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816}
817
818/*
819 * The permissions for the special ACL entries (u::, g::[m::], o::) are
820 * actually stored in the file mode (if there is both a group and a mask,
821 * the group is stored in the ACL entry and the mask is stored on the file).
822 * This allows the mode to remain automatically in sync with the ACL without
823 * the need for a call-back to the ACL system at every point where the mode
824 * could change. This function takes the permissions from the specified mode
825 * and places it in the supplied ACL.
826 *
827 * This implementation draws its validity from the fact that, when the ACL
828 * was assigned, the mode was copied from the ACL.
829 * If the mode did not change, therefore, the mode remains exactly what was
830 * taken from the special ACL entries at assignment.
831 * If a subsequent chmod() was done, the POSIX spec says that the change in
832 * mode must cause an update to the ACL seen at user level and used for
833 * access checks. Before and after a mode change, therefore, the file mode
834 * most accurately reflects what the special ACL entries should permit/deny.
835 *
836 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
837 * the existing mode bits will override whatever is in the
838 * ACL. Similarly, if there is a pre-existing ACL that was
839 * never in sync with its mode (owing to a bug in 6.5 and
840 * before), it will now magically (or mystically) be
841 * synchronized. This could cause slight astonishment, but
842 * it is better than inconsistent permissions.
843 *
844 * The supplied ACL is a template that may contain any combination
845 * of special entries. These are treated as place holders when we fill
846 * out the ACL. This routine does not add or remove special entries, it
847 * simply unites each special entry with its associated set of permissions.
848 */
849STATIC void
850xfs_acl_sync_mode(
851 mode_t mode,
852 xfs_acl_t *acl)
853{
854 int i, nomask = 1;
855 xfs_acl_entry_t *ap;
856 xfs_acl_entry_t *gap = NULL;
857
858 /*
859 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
860 * be set instead of the GROUP entry, if there is a MASK.
861 */
862 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
863 switch (ap->ae_tag) {
864 case ACL_USER_OBJ:
865 ap->ae_perm = (mode >> 6) & 0x7;
866 break;
867 case ACL_GROUP_OBJ:
868 gap = ap;
869 break;
870 case ACL_MASK:
871 nomask = 0;
872 ap->ae_perm = (mode >> 3) & 0x7;
873 break;
874 case ACL_OTHER:
875 ap->ae_perm = mode & 0x7;
876 break;
877 default:
878 break;
879 }
880 }
881 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
882 if (gap && nomask)
883 gap->ae_perm = (mode >> 3) & 0x7;
884}
885
886/*
887 * When inheriting an Access ACL from a directory Default ACL,
888 * the ACL bits are set to the intersection of the ACL default
889 * permission bits and the file permission bits in mode. If there
890 * are no permission bits on the file then we must not give them
891 * the ACL. This is what what makes umask() work with ACLs.
892 */
893STATIC void
894xfs_acl_filter_mode(
895 mode_t mode,
896 xfs_acl_t *acl)
897{
898 int i, nomask = 1;
899 xfs_acl_entry_t *ap;
900 xfs_acl_entry_t *gap = NULL;
901
902 /*
903 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
904 * be merged with GROUP entry, if there is a MASK.
905 */
906 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
907 switch (ap->ae_tag) {
908 case ACL_USER_OBJ:
909 ap->ae_perm &= (mode >> 6) & 0x7;
910 break;
911 case ACL_GROUP_OBJ:
912 gap = ap;
913 break;
914 case ACL_MASK:
915 nomask = 0;
916 ap->ae_perm &= (mode >> 3) & 0x7;
917 break;
918 case ACL_OTHER:
919 ap->ae_perm &= mode & 0x7;
920 break;
921 default:
922 break;
923 }
924 }
925 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
926 if (gap && nomask)
927 gap->ae_perm &= (mode >> 3) & 0x7;
928}