Commit | Line | Data |
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ef14f0c1 CH |
1 | /* |
2 | * Copyright (c) 2008, Christoph Hellwig | |
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_acl.h" | |
20 | #include "xfs_attr.h" | |
21 | #include "xfs_bmap_btree.h" | |
22 | #include "xfs_inode.h" | |
23 | #include "xfs_vnodeops.h" | |
0b1b213f | 24 | #include "xfs_trace.h" |
5a0e3ad6 | 25 | #include <linux/slab.h> |
ef14f0c1 CH |
26 | #include <linux/xattr.h> |
27 | #include <linux/posix_acl_xattr.h> | |
28 | ||
29 | ||
ef14f0c1 CH |
30 | /* |
31 | * Locking scheme: | |
32 | * - all ACL updates are protected by inode->i_mutex, which is taken before | |
33 | * calling into this file. | |
ef14f0c1 CH |
34 | */ |
35 | ||
36 | STATIC struct posix_acl * | |
37 | xfs_acl_from_disk(struct xfs_acl *aclp) | |
38 | { | |
39 | struct posix_acl_entry *acl_e; | |
40 | struct posix_acl *acl; | |
41 | struct xfs_acl_entry *ace; | |
42 | int count, i; | |
43 | ||
44 | count = be32_to_cpu(aclp->acl_cnt); | |
45 | ||
46 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
47 | if (!acl) | |
48 | return ERR_PTR(-ENOMEM); | |
49 | ||
50 | for (i = 0; i < count; i++) { | |
51 | acl_e = &acl->a_entries[i]; | |
52 | ace = &aclp->acl_entry[i]; | |
53 | ||
54 | /* | |
55 | * The tag is 32 bits on disk and 16 bits in core. | |
56 | * | |
57 | * Because every access to it goes through the core | |
58 | * format first this is not a problem. | |
59 | */ | |
60 | acl_e->e_tag = be32_to_cpu(ace->ae_tag); | |
61 | acl_e->e_perm = be16_to_cpu(ace->ae_perm); | |
62 | ||
63 | switch (acl_e->e_tag) { | |
64 | case ACL_USER: | |
65 | case ACL_GROUP: | |
66 | acl_e->e_id = be32_to_cpu(ace->ae_id); | |
67 | break; | |
68 | case ACL_USER_OBJ: | |
69 | case ACL_GROUP_OBJ: | |
70 | case ACL_MASK: | |
71 | case ACL_OTHER: | |
72 | acl_e->e_id = ACL_UNDEFINED_ID; | |
73 | break; | |
74 | default: | |
75 | goto fail; | |
76 | } | |
77 | } | |
78 | return acl; | |
79 | ||
80 | fail: | |
81 | posix_acl_release(acl); | |
82 | return ERR_PTR(-EINVAL); | |
83 | } | |
84 | ||
85 | STATIC void | |
86 | xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) | |
87 | { | |
88 | const struct posix_acl_entry *acl_e; | |
89 | struct xfs_acl_entry *ace; | |
90 | int i; | |
91 | ||
92 | aclp->acl_cnt = cpu_to_be32(acl->a_count); | |
93 | for (i = 0; i < acl->a_count; i++) { | |
94 | ace = &aclp->acl_entry[i]; | |
95 | acl_e = &acl->a_entries[i]; | |
96 | ||
97 | ace->ae_tag = cpu_to_be32(acl_e->e_tag); | |
98 | ace->ae_id = cpu_to_be32(acl_e->e_id); | |
99 | ace->ae_perm = cpu_to_be16(acl_e->e_perm); | |
100 | } | |
101 | } | |
102 | ||
ef14f0c1 CH |
103 | struct posix_acl * |
104 | xfs_get_acl(struct inode *inode, int type) | |
105 | { | |
106 | struct xfs_inode *ip = XFS_I(inode); | |
1cbd20d8 | 107 | struct posix_acl *acl; |
ef14f0c1 CH |
108 | struct xfs_acl *xfs_acl; |
109 | int len = sizeof(struct xfs_acl); | |
a9273ca5 | 110 | unsigned char *ea_name; |
ef14f0c1 CH |
111 | int error; |
112 | ||
1cbd20d8 AV |
113 | acl = get_cached_acl(inode, type); |
114 | if (acl != ACL_NOT_CACHED) | |
115 | return acl; | |
116 | ||
ef14f0c1 CH |
117 | switch (type) { |
118 | case ACL_TYPE_ACCESS: | |
119 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
120 | break; |
121 | case ACL_TYPE_DEFAULT: | |
122 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
123 | break; |
124 | default: | |
1cbd20d8 | 125 | BUG(); |
ef14f0c1 CH |
126 | } |
127 | ||
ef14f0c1 CH |
128 | /* |
129 | * If we have a cached ACLs value just return it, not need to | |
130 | * go out to the disk. | |
131 | */ | |
ef14f0c1 CH |
132 | |
133 | xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL); | |
134 | if (!xfs_acl) | |
135 | return ERR_PTR(-ENOMEM); | |
136 | ||
a9273ca5 DC |
137 | error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl, |
138 | &len, ATTR_ROOT); | |
ef14f0c1 CH |
139 | if (error) { |
140 | /* | |
141 | * If the attribute doesn't exist make sure we have a negative | |
142 | * cache entry, for any other error assume it is transient and | |
1cbd20d8 | 143 | * leave the cache entry as ACL_NOT_CACHED. |
ef14f0c1 CH |
144 | */ |
145 | if (error == -ENOATTR) { | |
146 | acl = NULL; | |
147 | goto out_update_cache; | |
148 | } | |
149 | goto out; | |
150 | } | |
151 | ||
152 | acl = xfs_acl_from_disk(xfs_acl); | |
153 | if (IS_ERR(acl)) | |
154 | goto out; | |
155 | ||
156 | out_update_cache: | |
1cbd20d8 | 157 | set_cached_acl(inode, type, acl); |
ef14f0c1 CH |
158 | out: |
159 | kfree(xfs_acl); | |
160 | return acl; | |
161 | } | |
162 | ||
163 | STATIC int | |
164 | xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
165 | { | |
166 | struct xfs_inode *ip = XFS_I(inode); | |
a9273ca5 | 167 | unsigned char *ea_name; |
ef14f0c1 CH |
168 | int error; |
169 | ||
170 | if (S_ISLNK(inode->i_mode)) | |
171 | return -EOPNOTSUPP; | |
172 | ||
173 | switch (type) { | |
174 | case ACL_TYPE_ACCESS: | |
175 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
176 | break; |
177 | case ACL_TYPE_DEFAULT: | |
178 | if (!S_ISDIR(inode->i_mode)) | |
179 | return acl ? -EACCES : 0; | |
180 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
181 | break; |
182 | default: | |
183 | return -EINVAL; | |
184 | } | |
185 | ||
186 | if (acl) { | |
187 | struct xfs_acl *xfs_acl; | |
188 | int len; | |
189 | ||
190 | xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL); | |
191 | if (!xfs_acl) | |
192 | return -ENOMEM; | |
193 | ||
194 | xfs_acl_to_disk(xfs_acl, acl); | |
195 | len = sizeof(struct xfs_acl) - | |
196 | (sizeof(struct xfs_acl_entry) * | |
197 | (XFS_ACL_MAX_ENTRIES - acl->a_count)); | |
198 | ||
a9273ca5 | 199 | error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl, |
ef14f0c1 CH |
200 | len, ATTR_ROOT); |
201 | ||
202 | kfree(xfs_acl); | |
203 | } else { | |
204 | /* | |
205 | * A NULL ACL argument means we want to remove the ACL. | |
206 | */ | |
207 | error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT); | |
208 | ||
209 | /* | |
210 | * If the attribute didn't exist to start with that's fine. | |
211 | */ | |
212 | if (error == -ENOATTR) | |
213 | error = 0; | |
214 | } | |
215 | ||
216 | if (!error) | |
1cbd20d8 | 217 | set_cached_acl(inode, type, acl); |
ef14f0c1 CH |
218 | return error; |
219 | } | |
220 | ||
221 | int | |
b74c79e9 | 222 | xfs_check_acl(struct inode *inode, int mask, unsigned int flags) |
ef14f0c1 | 223 | { |
b74c79e9 | 224 | struct xfs_inode *ip; |
ef14f0c1 CH |
225 | struct posix_acl *acl; |
226 | int error = -EAGAIN; | |
227 | ||
b74c79e9 NP |
228 | if (flags & IPERM_FLAG_RCU) |
229 | return -ECHILD; | |
230 | ||
231 | ip = XFS_I(inode); | |
cca28fb8 | 232 | trace_xfs_check_acl(ip); |
ef14f0c1 CH |
233 | |
234 | /* | |
235 | * If there is no attribute fork no ACL exists on this inode and | |
236 | * we can skip the whole exercise. | |
237 | */ | |
238 | if (!XFS_IFORK_Q(ip)) | |
239 | return -EAGAIN; | |
240 | ||
241 | acl = xfs_get_acl(inode, ACL_TYPE_ACCESS); | |
242 | if (IS_ERR(acl)) | |
243 | return PTR_ERR(acl); | |
244 | if (acl) { | |
245 | error = posix_acl_permission(inode, acl, mask); | |
246 | posix_acl_release(acl); | |
247 | } | |
248 | ||
249 | return error; | |
250 | } | |
251 | ||
252 | static int | |
253 | xfs_set_mode(struct inode *inode, mode_t mode) | |
254 | { | |
255 | int error = 0; | |
256 | ||
257 | if (mode != inode->i_mode) { | |
258 | struct iattr iattr; | |
259 | ||
d6d59bad | 260 | iattr.ia_valid = ATTR_MODE | ATTR_CTIME; |
ef14f0c1 | 261 | iattr.ia_mode = mode; |
d6d59bad | 262 | iattr.ia_ctime = current_fs_time(inode->i_sb); |
ef14f0c1 CH |
263 | |
264 | error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL); | |
265 | } | |
266 | ||
267 | return error; | |
268 | } | |
269 | ||
270 | static int | |
a9273ca5 | 271 | xfs_acl_exists(struct inode *inode, unsigned char *name) |
ef14f0c1 CH |
272 | { |
273 | int len = sizeof(struct xfs_acl); | |
274 | ||
275 | return (xfs_attr_get(XFS_I(inode), name, NULL, &len, | |
276 | ATTR_ROOT|ATTR_KERNOVAL) == 0); | |
277 | } | |
278 | ||
279 | int | |
280 | posix_acl_access_exists(struct inode *inode) | |
281 | { | |
282 | return xfs_acl_exists(inode, SGI_ACL_FILE); | |
283 | } | |
284 | ||
285 | int | |
286 | posix_acl_default_exists(struct inode *inode) | |
287 | { | |
288 | if (!S_ISDIR(inode->i_mode)) | |
289 | return 0; | |
290 | return xfs_acl_exists(inode, SGI_ACL_DEFAULT); | |
291 | } | |
292 | ||
293 | /* | |
294 | * No need for i_mutex because the inode is not yet exposed to the VFS. | |
295 | */ | |
296 | int | |
297 | xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl) | |
298 | { | |
299 | struct posix_acl *clone; | |
300 | mode_t mode; | |
301 | int error = 0, inherit = 0; | |
302 | ||
303 | if (S_ISDIR(inode->i_mode)) { | |
304 | error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl); | |
305 | if (error) | |
306 | return error; | |
307 | } | |
308 | ||
309 | clone = posix_acl_clone(default_acl, GFP_KERNEL); | |
310 | if (!clone) | |
311 | return -ENOMEM; | |
312 | ||
313 | mode = inode->i_mode; | |
314 | error = posix_acl_create_masq(clone, &mode); | |
315 | if (error < 0) | |
316 | goto out_release_clone; | |
317 | ||
318 | /* | |
319 | * If posix_acl_create_masq returns a positive value we need to | |
320 | * inherit a permission that can't be represented using the Unix | |
321 | * mode bits and we actually need to set an ACL. | |
322 | */ | |
323 | if (error > 0) | |
324 | inherit = 1; | |
325 | ||
326 | error = xfs_set_mode(inode, mode); | |
327 | if (error) | |
328 | goto out_release_clone; | |
329 | ||
330 | if (inherit) | |
331 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
332 | ||
333 | out_release_clone: | |
334 | posix_acl_release(clone); | |
335 | return error; | |
336 | } | |
337 | ||
338 | int | |
339 | xfs_acl_chmod(struct inode *inode) | |
340 | { | |
341 | struct posix_acl *acl, *clone; | |
342 | int error; | |
343 | ||
344 | if (S_ISLNK(inode->i_mode)) | |
345 | return -EOPNOTSUPP; | |
346 | ||
347 | acl = xfs_get_acl(inode, ACL_TYPE_ACCESS); | |
348 | if (IS_ERR(acl) || !acl) | |
349 | return PTR_ERR(acl); | |
350 | ||
351 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
352 | posix_acl_release(acl); | |
353 | if (!clone) | |
354 | return -ENOMEM; | |
355 | ||
356 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
357 | if (!error) | |
358 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
359 | ||
360 | posix_acl_release(clone); | |
361 | return error; | |
362 | } | |
363 | ||
ef14f0c1 | 364 | static int |
431547b3 CH |
365 | xfs_xattr_acl_get(struct dentry *dentry, const char *name, |
366 | void *value, size_t size, int type) | |
ef14f0c1 CH |
367 | { |
368 | struct posix_acl *acl; | |
431547b3 | 369 | int error; |
ef14f0c1 | 370 | |
431547b3 | 371 | acl = xfs_get_acl(dentry->d_inode, type); |
ef14f0c1 CH |
372 | if (IS_ERR(acl)) |
373 | return PTR_ERR(acl); | |
374 | if (acl == NULL) | |
375 | return -ENODATA; | |
376 | ||
377 | error = posix_acl_to_xattr(acl, value, size); | |
378 | posix_acl_release(acl); | |
379 | ||
380 | return error; | |
381 | } | |
382 | ||
383 | static int | |
431547b3 CH |
384 | xfs_xattr_acl_set(struct dentry *dentry, const char *name, |
385 | const void *value, size_t size, int flags, int type) | |
ef14f0c1 | 386 | { |
431547b3 | 387 | struct inode *inode = dentry->d_inode; |
ef14f0c1 | 388 | struct posix_acl *acl = NULL; |
431547b3 | 389 | int error = 0; |
ef14f0c1 | 390 | |
ef14f0c1 CH |
391 | if (flags & XATTR_CREATE) |
392 | return -EINVAL; | |
393 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) | |
394 | return value ? -EACCES : 0; | |
395 | if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER)) | |
396 | return -EPERM; | |
397 | ||
398 | if (!value) | |
399 | goto set_acl; | |
400 | ||
401 | acl = posix_acl_from_xattr(value, size); | |
402 | if (!acl) { | |
403 | /* | |
404 | * acl_set_file(3) may request that we set default ACLs with | |
405 | * zero length -- defend (gracefully) against that here. | |
406 | */ | |
407 | goto out; | |
408 | } | |
409 | if (IS_ERR(acl)) { | |
410 | error = PTR_ERR(acl); | |
411 | goto out; | |
412 | } | |
413 | ||
414 | error = posix_acl_valid(acl); | |
415 | if (error) | |
416 | goto out_release; | |
417 | ||
418 | error = -EINVAL; | |
419 | if (acl->a_count > XFS_ACL_MAX_ENTRIES) | |
420 | goto out_release; | |
421 | ||
422 | if (type == ACL_TYPE_ACCESS) { | |
423 | mode_t mode = inode->i_mode; | |
424 | error = posix_acl_equiv_mode(acl, &mode); | |
425 | ||
426 | if (error <= 0) { | |
427 | posix_acl_release(acl); | |
428 | acl = NULL; | |
429 | ||
430 | if (error < 0) | |
431 | return error; | |
432 | } | |
433 | ||
434 | error = xfs_set_mode(inode, mode); | |
435 | if (error) | |
436 | goto out_release; | |
437 | } | |
438 | ||
439 | set_acl: | |
440 | error = xfs_set_acl(inode, type, acl); | |
441 | out_release: | |
442 | posix_acl_release(acl); | |
443 | out: | |
444 | return error; | |
445 | } | |
446 | ||
46e58764 | 447 | const struct xattr_handler xfs_xattr_acl_access_handler = { |
431547b3 CH |
448 | .prefix = POSIX_ACL_XATTR_ACCESS, |
449 | .flags = ACL_TYPE_ACCESS, | |
450 | .get = xfs_xattr_acl_get, | |
451 | .set = xfs_xattr_acl_set, | |
452 | }; | |
453 | ||
46e58764 | 454 | const struct xattr_handler xfs_xattr_acl_default_handler = { |
431547b3 CH |
455 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
456 | .flags = ACL_TYPE_DEFAULT, | |
457 | .get = xfs_xattr_acl_get, | |
458 | .set = xfs_xattr_acl_set, | |
ef14f0c1 | 459 | }; |