Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/acl.c |
ac27a0ec DK |
3 | * |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | */ | |
6 | ||
7 | #include <linux/init.h> | |
8 | #include <linux/sched.h> | |
9 | #include <linux/slab.h> | |
10 | #include <linux/capability.h> | |
11 | #include <linux/fs.h> | |
3dcf5451 CH |
12 | #include "ext4_jbd2.h" |
13 | #include "ext4.h" | |
ac27a0ec DK |
14 | #include "xattr.h" |
15 | #include "acl.h" | |
16 | ||
17 | /* | |
18 | * Convert from filesystem to in-memory representation. | |
19 | */ | |
20 | static struct posix_acl * | |
617ba13b | 21 | ext4_acl_from_disk(const void *value, size_t size) |
ac27a0ec DK |
22 | { |
23 | const char *end = (char *)value + size; | |
24 | int n, count; | |
25 | struct posix_acl *acl; | |
26 | ||
27 | if (!value) | |
28 | return NULL; | |
617ba13b | 29 | if (size < sizeof(ext4_acl_header)) |
ac27a0ec | 30 | return ERR_PTR(-EINVAL); |
617ba13b MC |
31 | if (((ext4_acl_header *)value)->a_version != |
32 | cpu_to_le32(EXT4_ACL_VERSION)) | |
ac27a0ec | 33 | return ERR_PTR(-EINVAL); |
617ba13b MC |
34 | value = (char *)value + sizeof(ext4_acl_header); |
35 | count = ext4_acl_count(size); | |
ac27a0ec DK |
36 | if (count < 0) |
37 | return ERR_PTR(-EINVAL); | |
38 | if (count == 0) | |
39 | return NULL; | |
216553c4 | 40 | acl = posix_acl_alloc(count, GFP_NOFS); |
ac27a0ec DK |
41 | if (!acl) |
42 | return ERR_PTR(-ENOMEM); | |
2b2d6d01 | 43 | for (n = 0; n < count; n++) { |
617ba13b MC |
44 | ext4_acl_entry *entry = |
45 | (ext4_acl_entry *)value; | |
46 | if ((char *)value + sizeof(ext4_acl_entry_short) > end) | |
ac27a0ec DK |
47 | goto fail; |
48 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
49 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
2b2d6d01 TT |
50 | |
51 | switch (acl->a_entries[n].e_tag) { | |
52 | case ACL_USER_OBJ: | |
53 | case ACL_GROUP_OBJ: | |
54 | case ACL_MASK: | |
55 | case ACL_OTHER: | |
56 | value = (char *)value + | |
57 | sizeof(ext4_acl_entry_short); | |
58 | acl->a_entries[n].e_id = ACL_UNDEFINED_ID; | |
59 | break; | |
60 | ||
61 | case ACL_USER: | |
62 | case ACL_GROUP: | |
63 | value = (char *)value + sizeof(ext4_acl_entry); | |
64 | if ((char *)value > end) | |
ac27a0ec | 65 | goto fail; |
2b2d6d01 TT |
66 | acl->a_entries[n].e_id = |
67 | le32_to_cpu(entry->e_id); | |
68 | break; | |
69 | ||
70 | default: | |
71 | goto fail; | |
ac27a0ec DK |
72 | } |
73 | } | |
74 | if (value != end) | |
75 | goto fail; | |
76 | return acl; | |
77 | ||
78 | fail: | |
79 | posix_acl_release(acl); | |
80 | return ERR_PTR(-EINVAL); | |
81 | } | |
82 | ||
83 | /* | |
84 | * Convert from in-memory to filesystem representation. | |
85 | */ | |
86 | static void * | |
617ba13b | 87 | ext4_acl_to_disk(const struct posix_acl *acl, size_t *size) |
ac27a0ec | 88 | { |
617ba13b | 89 | ext4_acl_header *ext_acl; |
ac27a0ec DK |
90 | char *e; |
91 | size_t n; | |
92 | ||
617ba13b MC |
93 | *size = ext4_acl_size(acl->a_count); |
94 | ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count * | |
216553c4 | 95 | sizeof(ext4_acl_entry), GFP_NOFS); |
ac27a0ec DK |
96 | if (!ext_acl) |
97 | return ERR_PTR(-ENOMEM); | |
617ba13b MC |
98 | ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION); |
99 | e = (char *)ext_acl + sizeof(ext4_acl_header); | |
2b2d6d01 | 100 | for (n = 0; n < acl->a_count; n++) { |
617ba13b | 101 | ext4_acl_entry *entry = (ext4_acl_entry *)e; |
ac27a0ec DK |
102 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); |
103 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
2b2d6d01 TT |
104 | switch (acl->a_entries[n].e_tag) { |
105 | case ACL_USER: | |
106 | case ACL_GROUP: | |
107 | entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); | |
108 | e += sizeof(ext4_acl_entry); | |
109 | break; | |
110 | ||
111 | case ACL_USER_OBJ: | |
112 | case ACL_GROUP_OBJ: | |
113 | case ACL_MASK: | |
114 | case ACL_OTHER: | |
115 | e += sizeof(ext4_acl_entry_short); | |
116 | break; | |
117 | ||
118 | default: | |
119 | goto fail; | |
ac27a0ec DK |
120 | } |
121 | } | |
122 | return (char *)ext_acl; | |
123 | ||
124 | fail: | |
125 | kfree(ext_acl); | |
126 | return ERR_PTR(-EINVAL); | |
127 | } | |
128 | ||
ac27a0ec DK |
129 | /* |
130 | * Inode operation get_posix_acl(). | |
131 | * | |
132 | * inode->i_mutex: don't care | |
133 | */ | |
4e34e719 | 134 | struct posix_acl * |
617ba13b | 135 | ext4_get_acl(struct inode *inode, int type) |
ac27a0ec | 136 | { |
ac27a0ec DK |
137 | int name_index; |
138 | char *value = NULL; | |
139 | struct posix_acl *acl; | |
140 | int retval; | |
141 | ||
142 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
143 | return NULL; | |
144 | ||
073aaa1b AV |
145 | acl = get_cached_acl(inode, type); |
146 | if (acl != ACL_NOT_CACHED) | |
147 | return acl; | |
148 | ||
2b2d6d01 TT |
149 | switch (type) { |
150 | case ACL_TYPE_ACCESS: | |
2b2d6d01 TT |
151 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; |
152 | break; | |
2b2d6d01 | 153 | case ACL_TYPE_DEFAULT: |
2b2d6d01 TT |
154 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; |
155 | break; | |
2b2d6d01 | 156 | default: |
073aaa1b | 157 | BUG(); |
ac27a0ec | 158 | } |
617ba13b | 159 | retval = ext4_xattr_get(inode, name_index, "", NULL, 0); |
ac27a0ec | 160 | if (retval > 0) { |
216553c4 | 161 | value = kmalloc(retval, GFP_NOFS); |
ac27a0ec DK |
162 | if (!value) |
163 | return ERR_PTR(-ENOMEM); | |
617ba13b | 164 | retval = ext4_xattr_get(inode, name_index, "", value, retval); |
ac27a0ec DK |
165 | } |
166 | if (retval > 0) | |
617ba13b | 167 | acl = ext4_acl_from_disk(value, retval); |
ac27a0ec DK |
168 | else if (retval == -ENODATA || retval == -ENOSYS) |
169 | acl = NULL; | |
170 | else | |
171 | acl = ERR_PTR(retval); | |
172 | kfree(value); | |
173 | ||
073aaa1b AV |
174 | if (!IS_ERR(acl)) |
175 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 176 | |
ac27a0ec DK |
177 | return acl; |
178 | } | |
179 | ||
180 | /* | |
181 | * Set the access or default ACL of an inode. | |
182 | * | |
617ba13b | 183 | * inode->i_mutex: down unless called from ext4_new_inode |
ac27a0ec DK |
184 | */ |
185 | static int | |
617ba13b | 186 | ext4_set_acl(handle_t *handle, struct inode *inode, int type, |
ac27a0ec DK |
187 | struct posix_acl *acl) |
188 | { | |
ac27a0ec DK |
189 | int name_index; |
190 | void *value = NULL; | |
191 | size_t size = 0; | |
192 | int error; | |
193 | ||
194 | if (S_ISLNK(inode->i_mode)) | |
195 | return -EOPNOTSUPP; | |
196 | ||
2b2d6d01 TT |
197 | switch (type) { |
198 | case ACL_TYPE_ACCESS: | |
199 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; | |
200 | if (acl) { | |
d6952123 | 201 | error = posix_acl_equiv_mode(acl, &inode->i_mode); |
2b2d6d01 TT |
202 | if (error < 0) |
203 | return error; | |
204 | else { | |
c6ac12a6 | 205 | inode->i_ctime = ext4_current_time(inode); |
2b2d6d01 TT |
206 | ext4_mark_inode_dirty(handle, inode); |
207 | if (error == 0) | |
208 | acl = NULL; | |
ac27a0ec | 209 | } |
2b2d6d01 TT |
210 | } |
211 | break; | |
ac27a0ec | 212 | |
2b2d6d01 TT |
213 | case ACL_TYPE_DEFAULT: |
214 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
215 | if (!S_ISDIR(inode->i_mode)) | |
216 | return acl ? -EACCES : 0; | |
217 | break; | |
ac27a0ec | 218 | |
2b2d6d01 TT |
219 | default: |
220 | return -EINVAL; | |
ac27a0ec DK |
221 | } |
222 | if (acl) { | |
617ba13b | 223 | value = ext4_acl_to_disk(acl, &size); |
ac27a0ec DK |
224 | if (IS_ERR(value)) |
225 | return (int)PTR_ERR(value); | |
226 | } | |
227 | ||
617ba13b | 228 | error = ext4_xattr_set_handle(handle, inode, name_index, "", |
ac27a0ec DK |
229 | value, size, 0); |
230 | ||
231 | kfree(value); | |
073aaa1b AV |
232 | if (!error) |
233 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 234 | |
ac27a0ec DK |
235 | return error; |
236 | } | |
237 | ||
ac27a0ec | 238 | /* |
617ba13b | 239 | * Initialize the ACLs of a new inode. Called from ext4_new_inode. |
ac27a0ec DK |
240 | * |
241 | * dir->i_mutex: down | |
242 | * inode->i_mutex: up (access to inode is still exclusive) | |
243 | */ | |
244 | int | |
617ba13b | 245 | ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) |
ac27a0ec DK |
246 | { |
247 | struct posix_acl *acl = NULL; | |
248 | int error = 0; | |
249 | ||
250 | if (!S_ISLNK(inode->i_mode)) { | |
251 | if (test_opt(dir->i_sb, POSIX_ACL)) { | |
617ba13b | 252 | acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT); |
ac27a0ec DK |
253 | if (IS_ERR(acl)) |
254 | return PTR_ERR(acl); | |
255 | } | |
256 | if (!acl) | |
ce3b0f8d | 257 | inode->i_mode &= ~current_umask(); |
ac27a0ec DK |
258 | } |
259 | if (test_opt(inode->i_sb, POSIX_ACL) && acl) { | |
ac27a0ec | 260 | if (S_ISDIR(inode->i_mode)) { |
617ba13b | 261 | error = ext4_set_acl(handle, inode, |
ac27a0ec DK |
262 | ACL_TYPE_DEFAULT, acl); |
263 | if (error) | |
264 | goto cleanup; | |
265 | } | |
d3fb6120 | 266 | error = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode); |
826cae2f AV |
267 | if (error < 0) |
268 | return error; | |
269 | ||
826cae2f AV |
270 | if (error > 0) { |
271 | /* This is an extended ACL */ | |
272 | error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl); | |
ac27a0ec | 273 | } |
ac27a0ec DK |
274 | } |
275 | cleanup: | |
276 | posix_acl_release(acl); | |
277 | return error; | |
278 | } | |
279 | ||
280 | /* | |
281 | * Does chmod for an inode that may have an Access Control List. The | |
282 | * inode->i_mode field must be updated to the desired value by the caller | |
283 | * before calling this function. | |
284 | * Returns 0 on success, or a negative error number. | |
285 | * | |
286 | * We change the ACL rather than storing some ACL entries in the file | |
287 | * mode permission bits (which would be more efficient), because that | |
288 | * would break once additional permissions (like ACL_APPEND, ACL_DELETE | |
289 | * for directories) are added. There are no more bits available in the | |
290 | * file mode. | |
291 | * | |
292 | * inode->i_mutex: down | |
293 | */ | |
294 | int | |
617ba13b | 295 | ext4_acl_chmod(struct inode *inode) |
ac27a0ec | 296 | { |
bc26ab5f AV |
297 | struct posix_acl *acl; |
298 | handle_t *handle; | |
299 | int retries = 0; | |
63f57933 | 300 | int error; |
ac27a0ec | 301 | |
bc26ab5f | 302 | |
ac27a0ec DK |
303 | if (S_ISLNK(inode->i_mode)) |
304 | return -EOPNOTSUPP; | |
305 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
306 | return 0; | |
617ba13b | 307 | acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); |
ac27a0ec DK |
308 | if (IS_ERR(acl) || !acl) |
309 | return PTR_ERR(acl); | |
bc26ab5f AV |
310 | error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); |
311 | if (error) | |
312 | return error; | |
313 | retry: | |
314 | handle = ext4_journal_start(inode, | |
315 | EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); | |
316 | if (IS_ERR(handle)) { | |
317 | error = PTR_ERR(handle); | |
318 | ext4_std_error(inode->i_sb, error); | |
319 | goto out; | |
ac27a0ec | 320 | } |
bc26ab5f AV |
321 | error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl); |
322 | ext4_journal_stop(handle); | |
323 | if (error == -ENOSPC && | |
324 | ext4_should_retry_alloc(inode->i_sb, &retries)) | |
325 | goto retry; | |
ac27a0ec | 326 | out: |
bc26ab5f | 327 | posix_acl_release(acl); |
ac27a0ec DK |
328 | return error; |
329 | } | |
330 | ||
331 | /* | |
332 | * Extended attribute handlers | |
333 | */ | |
334 | static size_t | |
431547b3 CH |
335 | ext4_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len, |
336 | const char *name, size_t name_len, int type) | |
ac27a0ec DK |
337 | { |
338 | const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); | |
339 | ||
431547b3 | 340 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
ac27a0ec DK |
341 | return 0; |
342 | if (list && size <= list_len) | |
343 | memcpy(list, POSIX_ACL_XATTR_ACCESS, size); | |
344 | return size; | |
345 | } | |
346 | ||
347 | static size_t | |
431547b3 CH |
348 | ext4_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len, |
349 | const char *name, size_t name_len, int type) | |
ac27a0ec DK |
350 | { |
351 | const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); | |
352 | ||
431547b3 | 353 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
ac27a0ec DK |
354 | return 0; |
355 | if (list && size <= list_len) | |
356 | memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); | |
357 | return size; | |
358 | } | |
359 | ||
360 | static int | |
431547b3 CH |
361 | ext4_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer, |
362 | size_t size, int type) | |
ac27a0ec DK |
363 | { |
364 | struct posix_acl *acl; | |
365 | int error; | |
366 | ||
431547b3 CH |
367 | if (strcmp(name, "") != 0) |
368 | return -EINVAL; | |
369 | if (!test_opt(dentry->d_sb, POSIX_ACL)) | |
ac27a0ec DK |
370 | return -EOPNOTSUPP; |
371 | ||
431547b3 | 372 | acl = ext4_get_acl(dentry->d_inode, type); |
ac27a0ec DK |
373 | if (IS_ERR(acl)) |
374 | return PTR_ERR(acl); | |
375 | if (acl == NULL) | |
376 | return -ENODATA; | |
377 | error = posix_acl_to_xattr(acl, buffer, size); | |
378 | posix_acl_release(acl); | |
379 | ||
380 | return error; | |
381 | } | |
382 | ||
383 | static int | |
431547b3 CH |
384 | ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value, |
385 | size_t size, int flags, int type) | |
ac27a0ec | 386 | { |
431547b3 | 387 | struct inode *inode = dentry->d_inode; |
ac27a0ec DK |
388 | handle_t *handle; |
389 | struct posix_acl *acl; | |
390 | int error, retries = 0; | |
391 | ||
431547b3 CH |
392 | if (strcmp(name, "") != 0) |
393 | return -EINVAL; | |
ac27a0ec DK |
394 | if (!test_opt(inode->i_sb, POSIX_ACL)) |
395 | return -EOPNOTSUPP; | |
2e149670 | 396 | if (!inode_owner_or_capable(inode)) |
ac27a0ec DK |
397 | return -EPERM; |
398 | ||
399 | if (value) { | |
400 | acl = posix_acl_from_xattr(value, size); | |
401 | if (IS_ERR(acl)) | |
402 | return PTR_ERR(acl); | |
403 | else if (acl) { | |
404 | error = posix_acl_valid(acl); | |
405 | if (error) | |
406 | goto release_and_out; | |
407 | } | |
408 | } else | |
409 | acl = NULL; | |
410 | ||
411 | retry: | |
617ba13b | 412 | handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); |
ac27a0ec DK |
413 | if (IS_ERR(handle)) |
414 | return PTR_ERR(handle); | |
617ba13b MC |
415 | error = ext4_set_acl(handle, inode, type, acl); |
416 | ext4_journal_stop(handle); | |
417 | if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) | |
ac27a0ec DK |
418 | goto retry; |
419 | ||
420 | release_and_out: | |
421 | posix_acl_release(acl); | |
422 | return error; | |
423 | } | |
424 | ||
11e27528 | 425 | const struct xattr_handler ext4_xattr_acl_access_handler = { |
ac27a0ec | 426 | .prefix = POSIX_ACL_XATTR_ACCESS, |
431547b3 | 427 | .flags = ACL_TYPE_ACCESS, |
617ba13b | 428 | .list = ext4_xattr_list_acl_access, |
431547b3 CH |
429 | .get = ext4_xattr_get_acl, |
430 | .set = ext4_xattr_set_acl, | |
ac27a0ec DK |
431 | }; |
432 | ||
11e27528 | 433 | const struct xattr_handler ext4_xattr_acl_default_handler = { |
ac27a0ec | 434 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
431547b3 | 435 | .flags = ACL_TYPE_DEFAULT, |
617ba13b | 436 | .list = ext4_xattr_list_acl_default, |
431547b3 CH |
437 | .get = ext4_xattr_get_acl, |
438 | .set = ext4_xattr_set_acl, | |
ac27a0ec | 439 | }; |