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1 | #include <linux/capability.h> | |
2 | #include <linux/fs.h> | |
3 | #include <linux/posix_acl.h> | |
4 | #include <linux/reiserfs_fs.h> | |
5 | #include <linux/errno.h> | |
6 | #include <linux/pagemap.h> | |
7 | #include <linux/xattr.h> | |
8 | #include <linux/posix_acl_xattr.h> | |
9 | #include <linux/reiserfs_xattr.h> | |
10 | #include <linux/reiserfs_acl.h> | |
11 | #include <asm/uaccess.h> | |
12 | ||
13 | static int reiserfs_set_acl(struct inode *inode, int type, | |
14 | struct posix_acl *acl); | |
15 | ||
16 | static int | |
17 | xattr_set_acl(struct inode *inode, int type, const void *value, size_t size) | |
18 | { | |
19 | struct posix_acl *acl; | |
20 | int error; | |
21 | ||
22 | if (!reiserfs_posixacl(inode->i_sb)) | |
23 | return -EOPNOTSUPP; | |
24 | if (!is_owner_or_cap(inode)) | |
25 | return -EPERM; | |
26 | ||
27 | if (value) { | |
28 | acl = posix_acl_from_xattr(value, size); | |
29 | if (IS_ERR(acl)) { | |
30 | return PTR_ERR(acl); | |
31 | } else if (acl) { | |
32 | error = posix_acl_valid(acl); | |
33 | if (error) | |
34 | goto release_and_out; | |
35 | } | |
36 | } else | |
37 | acl = NULL; | |
38 | ||
39 | error = reiserfs_set_acl(inode, type, acl); | |
40 | ||
41 | release_and_out: | |
42 | posix_acl_release(acl); | |
43 | return error; | |
44 | } | |
45 | ||
46 | static int | |
47 | xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size) | |
48 | { | |
49 | struct posix_acl *acl; | |
50 | int error; | |
51 | ||
52 | if (!reiserfs_posixacl(inode->i_sb)) | |
53 | return -EOPNOTSUPP; | |
54 | ||
55 | acl = reiserfs_get_acl(inode, type); | |
56 | if (IS_ERR(acl)) | |
57 | return PTR_ERR(acl); | |
58 | if (acl == NULL) | |
59 | return -ENODATA; | |
60 | error = posix_acl_to_xattr(acl, buffer, size); | |
61 | posix_acl_release(acl); | |
62 | ||
63 | return error; | |
64 | } | |
65 | ||
66 | /* | |
67 | * Convert from filesystem to in-memory representation. | |
68 | */ | |
69 | static struct posix_acl *posix_acl_from_disk(const void *value, size_t size) | |
70 | { | |
71 | const char *end = (char *)value + size; | |
72 | int n, count; | |
73 | struct posix_acl *acl; | |
74 | ||
75 | if (!value) | |
76 | return NULL; | |
77 | if (size < sizeof(reiserfs_acl_header)) | |
78 | return ERR_PTR(-EINVAL); | |
79 | if (((reiserfs_acl_header *) value)->a_version != | |
80 | cpu_to_le32(REISERFS_ACL_VERSION)) | |
81 | return ERR_PTR(-EINVAL); | |
82 | value = (char *)value + sizeof(reiserfs_acl_header); | |
83 | count = reiserfs_acl_count(size); | |
84 | if (count < 0) | |
85 | return ERR_PTR(-EINVAL); | |
86 | if (count == 0) | |
87 | return NULL; | |
88 | acl = posix_acl_alloc(count, GFP_NOFS); | |
89 | if (!acl) | |
90 | return ERR_PTR(-ENOMEM); | |
91 | for (n = 0; n < count; n++) { | |
92 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; | |
93 | if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) | |
94 | goto fail; | |
95 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
96 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
97 | switch (acl->a_entries[n].e_tag) { | |
98 | case ACL_USER_OBJ: | |
99 | case ACL_GROUP_OBJ: | |
100 | case ACL_MASK: | |
101 | case ACL_OTHER: | |
102 | value = (char *)value + | |
103 | sizeof(reiserfs_acl_entry_short); | |
104 | acl->a_entries[n].e_id = ACL_UNDEFINED_ID; | |
105 | break; | |
106 | ||
107 | case ACL_USER: | |
108 | case ACL_GROUP: | |
109 | value = (char *)value + sizeof(reiserfs_acl_entry); | |
110 | if ((char *)value > end) | |
111 | goto fail; | |
112 | acl->a_entries[n].e_id = le32_to_cpu(entry->e_id); | |
113 | break; | |
114 | ||
115 | default: | |
116 | goto fail; | |
117 | } | |
118 | } | |
119 | if (value != end) | |
120 | goto fail; | |
121 | return acl; | |
122 | ||
123 | fail: | |
124 | posix_acl_release(acl); | |
125 | return ERR_PTR(-EINVAL); | |
126 | } | |
127 | ||
128 | /* | |
129 | * Convert from in-memory to filesystem representation. | |
130 | */ | |
131 | static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size) | |
132 | { | |
133 | reiserfs_acl_header *ext_acl; | |
134 | char *e; | |
135 | int n; | |
136 | ||
137 | *size = reiserfs_acl_size(acl->a_count); | |
138 | ext_acl = kmalloc(sizeof(reiserfs_acl_header) + | |
139 | acl->a_count * | |
140 | sizeof(reiserfs_acl_entry), | |
141 | GFP_NOFS); | |
142 | if (!ext_acl) | |
143 | return ERR_PTR(-ENOMEM); | |
144 | ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); | |
145 | e = (char *)ext_acl + sizeof(reiserfs_acl_header); | |
146 | for (n = 0; n < acl->a_count; n++) { | |
147 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; | |
148 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); | |
149 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
150 | switch (acl->a_entries[n].e_tag) { | |
151 | case ACL_USER: | |
152 | case ACL_GROUP: | |
153 | entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); | |
154 | e += sizeof(reiserfs_acl_entry); | |
155 | break; | |
156 | ||
157 | case ACL_USER_OBJ: | |
158 | case ACL_GROUP_OBJ: | |
159 | case ACL_MASK: | |
160 | case ACL_OTHER: | |
161 | e += sizeof(reiserfs_acl_entry_short); | |
162 | break; | |
163 | ||
164 | default: | |
165 | goto fail; | |
166 | } | |
167 | } | |
168 | return (char *)ext_acl; | |
169 | ||
170 | fail: | |
171 | kfree(ext_acl); | |
172 | return ERR_PTR(-EINVAL); | |
173 | } | |
174 | ||
175 | /* | |
176 | * Inode operation get_posix_acl(). | |
177 | * | |
178 | * inode->i_mutex: down | |
179 | * BKL held [before 2.5.x] | |
180 | */ | |
181 | struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) | |
182 | { | |
183 | char *name, *value; | |
184 | struct posix_acl *acl, **p_acl; | |
185 | int size; | |
186 | int retval; | |
187 | struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); | |
188 | ||
189 | switch (type) { | |
190 | case ACL_TYPE_ACCESS: | |
191 | name = POSIX_ACL_XATTR_ACCESS; | |
192 | p_acl = &reiserfs_i->i_acl_access; | |
193 | break; | |
194 | case ACL_TYPE_DEFAULT: | |
195 | name = POSIX_ACL_XATTR_DEFAULT; | |
196 | p_acl = &reiserfs_i->i_acl_default; | |
197 | break; | |
198 | default: | |
199 | return ERR_PTR(-EINVAL); | |
200 | } | |
201 | ||
202 | if (IS_ERR(*p_acl)) { | |
203 | if (PTR_ERR(*p_acl) == -ENODATA) | |
204 | return NULL; | |
205 | } else if (*p_acl != NULL) | |
206 | return posix_acl_dup(*p_acl); | |
207 | ||
208 | size = reiserfs_xattr_get(inode, name, NULL, 0); | |
209 | if (size < 0) { | |
210 | if (size == -ENODATA || size == -ENOSYS) { | |
211 | *p_acl = ERR_PTR(-ENODATA); | |
212 | return NULL; | |
213 | } | |
214 | return ERR_PTR(size); | |
215 | } | |
216 | ||
217 | value = kmalloc(size, GFP_NOFS); | |
218 | if (!value) | |
219 | return ERR_PTR(-ENOMEM); | |
220 | ||
221 | retval = reiserfs_xattr_get(inode, name, value, size); | |
222 | if (retval == -ENODATA || retval == -ENOSYS) { | |
223 | /* This shouldn't actually happen as it should have | |
224 | been caught above.. but just in case */ | |
225 | acl = NULL; | |
226 | *p_acl = ERR_PTR(-ENODATA); | |
227 | } else if (retval < 0) { | |
228 | acl = ERR_PTR(retval); | |
229 | } else { | |
230 | acl = posix_acl_from_disk(value, retval); | |
231 | if (!IS_ERR(acl)) | |
232 | *p_acl = posix_acl_dup(acl); | |
233 | } | |
234 | ||
235 | kfree(value); | |
236 | return acl; | |
237 | } | |
238 | ||
239 | /* | |
240 | * Inode operation set_posix_acl(). | |
241 | * | |
242 | * inode->i_mutex: down | |
243 | * BKL held [before 2.5.x] | |
244 | */ | |
245 | static int | |
246 | reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
247 | { | |
248 | char *name; | |
249 | void *value = NULL; | |
250 | struct posix_acl **p_acl; | |
251 | size_t size; | |
252 | int error; | |
253 | struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); | |
254 | ||
255 | if (S_ISLNK(inode->i_mode)) | |
256 | return -EOPNOTSUPP; | |
257 | ||
258 | switch (type) { | |
259 | case ACL_TYPE_ACCESS: | |
260 | name = POSIX_ACL_XATTR_ACCESS; | |
261 | p_acl = &reiserfs_i->i_acl_access; | |
262 | if (acl) { | |
263 | mode_t mode = inode->i_mode; | |
264 | error = posix_acl_equiv_mode(acl, &mode); | |
265 | if (error < 0) | |
266 | return error; | |
267 | else { | |
268 | inode->i_mode = mode; | |
269 | if (error == 0) | |
270 | acl = NULL; | |
271 | } | |
272 | } | |
273 | break; | |
274 | case ACL_TYPE_DEFAULT: | |
275 | name = POSIX_ACL_XATTR_DEFAULT; | |
276 | p_acl = &reiserfs_i->i_acl_default; | |
277 | if (!S_ISDIR(inode->i_mode)) | |
278 | return acl ? -EACCES : 0; | |
279 | break; | |
280 | default: | |
281 | return -EINVAL; | |
282 | } | |
283 | ||
284 | if (acl) { | |
285 | value = posix_acl_to_disk(acl, &size); | |
286 | if (IS_ERR(value)) | |
287 | return (int)PTR_ERR(value); | |
288 | error = reiserfs_xattr_set(inode, name, value, size, 0); | |
289 | } else { | |
290 | error = reiserfs_xattr_del(inode, name); | |
291 | if (error == -ENODATA) { | |
292 | /* This may seem odd here, but it means that the ACL was set | |
293 | * with a value representable with mode bits. If there was | |
294 | * an ACL before, reiserfs_xattr_del already dirtied the inode. | |
295 | */ | |
296 | mark_inode_dirty(inode); | |
297 | error = 0; | |
298 | } | |
299 | } | |
300 | ||
301 | kfree(value); | |
302 | ||
303 | if (!error) { | |
304 | /* Release the old one */ | |
305 | if (!IS_ERR(*p_acl) && *p_acl) | |
306 | posix_acl_release(*p_acl); | |
307 | ||
308 | if (acl == NULL) | |
309 | *p_acl = ERR_PTR(-ENODATA); | |
310 | else | |
311 | *p_acl = posix_acl_dup(acl); | |
312 | } | |
313 | ||
314 | return error; | |
315 | } | |
316 | ||
317 | /* dir->i_mutex: locked, | |
318 | * inode is new and not released into the wild yet */ | |
319 | int | |
320 | reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry, | |
321 | struct inode *inode) | |
322 | { | |
323 | struct posix_acl *acl; | |
324 | int err = 0; | |
325 | ||
326 | /* ACLs only get applied to files and directories */ | |
327 | if (S_ISLNK(inode->i_mode)) | |
328 | return 0; | |
329 | ||
330 | /* ACLs can only be used on "new" objects, so if it's an old object | |
331 | * there is nothing to inherit from */ | |
332 | if (get_inode_sd_version(dir) == STAT_DATA_V1) | |
333 | goto apply_umask; | |
334 | ||
335 | /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This | |
336 | * would be useless since permissions are ignored, and a pain because | |
337 | * it introduces locking cycles */ | |
338 | if (is_reiserfs_priv_object(dir)) { | |
339 | reiserfs_mark_inode_private(inode); | |
340 | goto apply_umask; | |
341 | } | |
342 | ||
343 | acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT); | |
344 | if (IS_ERR(acl)) { | |
345 | if (PTR_ERR(acl) == -ENODATA) | |
346 | goto apply_umask; | |
347 | return PTR_ERR(acl); | |
348 | } | |
349 | ||
350 | if (acl) { | |
351 | struct posix_acl *acl_copy; | |
352 | mode_t mode = inode->i_mode; | |
353 | int need_acl; | |
354 | ||
355 | /* Copy the default ACL to the default ACL of a new directory */ | |
356 | if (S_ISDIR(inode->i_mode)) { | |
357 | err = reiserfs_set_acl(inode, ACL_TYPE_DEFAULT, acl); | |
358 | if (err) | |
359 | goto cleanup; | |
360 | } | |
361 | ||
362 | /* Now we reconcile the new ACL and the mode, | |
363 | potentially modifying both */ | |
364 | acl_copy = posix_acl_clone(acl, GFP_NOFS); | |
365 | if (!acl_copy) { | |
366 | err = -ENOMEM; | |
367 | goto cleanup; | |
368 | } | |
369 | ||
370 | need_acl = posix_acl_create_masq(acl_copy, &mode); | |
371 | if (need_acl >= 0) { | |
372 | if (mode != inode->i_mode) { | |
373 | inode->i_mode = mode; | |
374 | } | |
375 | ||
376 | /* If we need an ACL.. */ | |
377 | if (need_acl > 0) { | |
378 | err = | |
379 | reiserfs_set_acl(inode, ACL_TYPE_ACCESS, | |
380 | acl_copy); | |
381 | if (err) | |
382 | goto cleanup_copy; | |
383 | } | |
384 | } | |
385 | cleanup_copy: | |
386 | posix_acl_release(acl_copy); | |
387 | cleanup: | |
388 | posix_acl_release(acl); | |
389 | } else { | |
390 | apply_umask: | |
391 | /* no ACL, apply umask */ | |
392 | inode->i_mode &= ~current->fs->umask; | |
393 | } | |
394 | ||
395 | return err; | |
396 | } | |
397 | ||
398 | /* Looks up and caches the result of the default ACL. | |
399 | * We do this so that we don't need to carry the xattr_sem into | |
400 | * reiserfs_new_inode if we don't need to */ | |
401 | int reiserfs_cache_default_acl(struct inode *inode) | |
402 | { | |
403 | int ret = 0; | |
404 | if (reiserfs_posixacl(inode->i_sb) && !is_reiserfs_priv_object(inode)) { | |
405 | struct posix_acl *acl; | |
406 | reiserfs_read_lock_xattr_i(inode); | |
407 | reiserfs_read_lock_xattrs(inode->i_sb); | |
408 | acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); | |
409 | reiserfs_read_unlock_xattrs(inode->i_sb); | |
410 | reiserfs_read_unlock_xattr_i(inode); | |
411 | ret = (acl && !IS_ERR(acl)); | |
412 | if (ret) | |
413 | posix_acl_release(acl); | |
414 | } | |
415 | ||
416 | return ret; | |
417 | } | |
418 | ||
419 | int reiserfs_acl_chmod(struct inode *inode) | |
420 | { | |
421 | struct posix_acl *acl, *clone; | |
422 | int error; | |
423 | ||
424 | if (S_ISLNK(inode->i_mode)) | |
425 | return -EOPNOTSUPP; | |
426 | ||
427 | if (get_inode_sd_version(inode) == STAT_DATA_V1 || | |
428 | !reiserfs_posixacl(inode->i_sb)) { | |
429 | return 0; | |
430 | } | |
431 | ||
432 | reiserfs_read_lock_xattrs(inode->i_sb); | |
433 | acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); | |
434 | reiserfs_read_unlock_xattrs(inode->i_sb); | |
435 | if (!acl) | |
436 | return 0; | |
437 | if (IS_ERR(acl)) | |
438 | return PTR_ERR(acl); | |
439 | clone = posix_acl_clone(acl, GFP_NOFS); | |
440 | posix_acl_release(acl); | |
441 | if (!clone) | |
442 | return -ENOMEM; | |
443 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
444 | if (!error) { | |
445 | int lock = !has_xattr_dir(inode); | |
446 | reiserfs_write_lock_xattr_i(inode); | |
447 | if (lock) | |
448 | reiserfs_write_lock_xattrs(inode->i_sb); | |
449 | else | |
450 | reiserfs_read_lock_xattrs(inode->i_sb); | |
451 | error = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
452 | if (lock) | |
453 | reiserfs_write_unlock_xattrs(inode->i_sb); | |
454 | else | |
455 | reiserfs_read_unlock_xattrs(inode->i_sb); | |
456 | reiserfs_write_unlock_xattr_i(inode); | |
457 | } | |
458 | posix_acl_release(clone); | |
459 | return error; | |
460 | } | |
461 | ||
462 | static int | |
463 | posix_acl_access_get(struct inode *inode, const char *name, | |
464 | void *buffer, size_t size) | |
465 | { | |
466 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) | |
467 | return -EINVAL; | |
468 | return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size); | |
469 | } | |
470 | ||
471 | static int | |
472 | posix_acl_access_set(struct inode *inode, const char *name, | |
473 | const void *value, size_t size, int flags) | |
474 | { | |
475 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) | |
476 | return -EINVAL; | |
477 | return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); | |
478 | } | |
479 | ||
480 | static int posix_acl_access_del(struct inode *inode, const char *name) | |
481 | { | |
482 | struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); | |
483 | struct posix_acl **acl = &reiserfs_i->i_acl_access; | |
484 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) | |
485 | return -EINVAL; | |
486 | if (!IS_ERR(*acl) && *acl) { | |
487 | posix_acl_release(*acl); | |
488 | *acl = ERR_PTR(-ENODATA); | |
489 | } | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
494 | static int | |
495 | posix_acl_access_list(struct inode *inode, const char *name, int namelen, | |
496 | char *out) | |
497 | { | |
498 | int len = namelen; | |
499 | if (!reiserfs_posixacl(inode->i_sb)) | |
500 | return 0; | |
501 | if (out) | |
502 | memcpy(out, name, len); | |
503 | ||
504 | return len; | |
505 | } | |
506 | ||
507 | struct reiserfs_xattr_handler posix_acl_access_handler = { | |
508 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
509 | .get = posix_acl_access_get, | |
510 | .set = posix_acl_access_set, | |
511 | .del = posix_acl_access_del, | |
512 | .list = posix_acl_access_list, | |
513 | }; | |
514 | ||
515 | static int | |
516 | posix_acl_default_get(struct inode *inode, const char *name, | |
517 | void *buffer, size_t size) | |
518 | { | |
519 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) | |
520 | return -EINVAL; | |
521 | return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size); | |
522 | } | |
523 | ||
524 | static int | |
525 | posix_acl_default_set(struct inode *inode, const char *name, | |
526 | const void *value, size_t size, int flags) | |
527 | { | |
528 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) | |
529 | return -EINVAL; | |
530 | return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); | |
531 | } | |
532 | ||
533 | static int posix_acl_default_del(struct inode *inode, const char *name) | |
534 | { | |
535 | struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); | |
536 | struct posix_acl **acl = &reiserfs_i->i_acl_default; | |
537 | if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) | |
538 | return -EINVAL; | |
539 | if (!IS_ERR(*acl) && *acl) { | |
540 | posix_acl_release(*acl); | |
541 | *acl = ERR_PTR(-ENODATA); | |
542 | } | |
543 | ||
544 | return 0; | |
545 | } | |
546 | ||
547 | static int | |
548 | posix_acl_default_list(struct inode *inode, const char *name, int namelen, | |
549 | char *out) | |
550 | { | |
551 | int len = namelen; | |
552 | if (!reiserfs_posixacl(inode->i_sb)) | |
553 | return 0; | |
554 | if (out) | |
555 | memcpy(out, name, len); | |
556 | ||
557 | return len; | |
558 | } | |
559 | ||
560 | struct reiserfs_xattr_handler posix_acl_default_handler = { | |
561 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
562 | .get = posix_acl_default_get, | |
563 | .set = posix_acl_default_set, | |
564 | .del = posix_acl_default_del, | |
565 | .list = posix_acl_default_list, | |
566 | }; |