Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ext2/acl.c | |
3 | * | |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | */ | |
6 | ||
16f7e0fe | 7 | #include <linux/capability.h> |
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/sched.h> | |
10 | #include <linux/slab.h> | |
11 | #include <linux/fs.h> | |
12 | #include "ext2.h" | |
13 | #include "xattr.h" | |
14 | #include "acl.h" | |
15 | ||
16 | /* | |
17 | * Convert from filesystem to in-memory representation. | |
18 | */ | |
19 | static struct posix_acl * | |
20 | ext2_acl_from_disk(const void *value, size_t size) | |
21 | { | |
22 | const char *end = (char *)value + size; | |
23 | int n, count; | |
24 | struct posix_acl *acl; | |
25 | ||
26 | if (!value) | |
27 | return NULL; | |
28 | if (size < sizeof(ext2_acl_header)) | |
29 | return ERR_PTR(-EINVAL); | |
30 | if (((ext2_acl_header *)value)->a_version != | |
31 | cpu_to_le32(EXT2_ACL_VERSION)) | |
32 | return ERR_PTR(-EINVAL); | |
33 | value = (char *)value + sizeof(ext2_acl_header); | |
34 | count = ext2_acl_count(size); | |
35 | if (count < 0) | |
36 | return ERR_PTR(-EINVAL); | |
37 | if (count == 0) | |
38 | return NULL; | |
39 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
40 | if (!acl) | |
41 | return ERR_PTR(-ENOMEM); | |
42 | for (n=0; n < count; n++) { | |
43 | ext2_acl_entry *entry = | |
44 | (ext2_acl_entry *)value; | |
45 | if ((char *)value + sizeof(ext2_acl_entry_short) > end) | |
46 | goto fail; | |
47 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
48 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
49 | switch(acl->a_entries[n].e_tag) { | |
50 | case ACL_USER_OBJ: | |
51 | case ACL_GROUP_OBJ: | |
52 | case ACL_MASK: | |
53 | case ACL_OTHER: | |
54 | value = (char *)value + | |
55 | sizeof(ext2_acl_entry_short); | |
56 | acl->a_entries[n].e_id = ACL_UNDEFINED_ID; | |
57 | break; | |
58 | ||
59 | case ACL_USER: | |
60 | case ACL_GROUP: | |
61 | value = (char *)value + sizeof(ext2_acl_entry); | |
62 | if ((char *)value > end) | |
63 | goto fail; | |
64 | acl->a_entries[n].e_id = | |
65 | le32_to_cpu(entry->e_id); | |
66 | break; | |
67 | ||
68 | default: | |
69 | goto fail; | |
70 | } | |
71 | } | |
72 | if (value != end) | |
73 | goto fail; | |
74 | return acl; | |
75 | ||
76 | fail: | |
77 | posix_acl_release(acl); | |
78 | return ERR_PTR(-EINVAL); | |
79 | } | |
80 | ||
81 | /* | |
82 | * Convert from in-memory to filesystem representation. | |
83 | */ | |
84 | static void * | |
85 | ext2_acl_to_disk(const struct posix_acl *acl, size_t *size) | |
86 | { | |
87 | ext2_acl_header *ext_acl; | |
88 | char *e; | |
89 | size_t n; | |
90 | ||
91 | *size = ext2_acl_size(acl->a_count); | |
f52720ca PI |
92 | ext_acl = kmalloc(sizeof(ext2_acl_header) + acl->a_count * |
93 | sizeof(ext2_acl_entry), GFP_KERNEL); | |
1da177e4 LT |
94 | if (!ext_acl) |
95 | return ERR_PTR(-ENOMEM); | |
96 | ext_acl->a_version = cpu_to_le32(EXT2_ACL_VERSION); | |
97 | e = (char *)ext_acl + sizeof(ext2_acl_header); | |
98 | for (n=0; n < acl->a_count; n++) { | |
99 | ext2_acl_entry *entry = (ext2_acl_entry *)e; | |
100 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); | |
101 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
102 | switch(acl->a_entries[n].e_tag) { | |
103 | case ACL_USER: | |
104 | case ACL_GROUP: | |
105 | entry->e_id = | |
106 | cpu_to_le32(acl->a_entries[n].e_id); | |
107 | e += sizeof(ext2_acl_entry); | |
108 | break; | |
109 | ||
110 | case ACL_USER_OBJ: | |
111 | case ACL_GROUP_OBJ: | |
112 | case ACL_MASK: | |
113 | case ACL_OTHER: | |
114 | e += sizeof(ext2_acl_entry_short); | |
115 | break; | |
116 | ||
117 | default: | |
118 | goto fail; | |
119 | } | |
120 | } | |
121 | return (char *)ext_acl; | |
122 | ||
123 | fail: | |
124 | kfree(ext_acl); | |
125 | return ERR_PTR(-EINVAL); | |
126 | } | |
127 | ||
1da177e4 | 128 | /* |
1b1dcc1b | 129 | * inode->i_mutex: don't care |
1da177e4 | 130 | */ |
4e34e719 | 131 | struct posix_acl * |
1da177e4 LT |
132 | ext2_get_acl(struct inode *inode, int type) |
133 | { | |
1da177e4 LT |
134 | int name_index; |
135 | char *value = NULL; | |
136 | struct posix_acl *acl; | |
137 | int retval; | |
138 | ||
139 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
140 | return NULL; | |
141 | ||
073aaa1b AV |
142 | acl = get_cached_acl(inode, type); |
143 | if (acl != ACL_NOT_CACHED) | |
144 | return acl; | |
145 | ||
146 | switch (type) { | |
147 | case ACL_TYPE_ACCESS: | |
148 | name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS; | |
149 | break; | |
150 | case ACL_TYPE_DEFAULT: | |
151 | name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
152 | break; | |
153 | default: | |
154 | BUG(); | |
1da177e4 LT |
155 | } |
156 | retval = ext2_xattr_get(inode, name_index, "", NULL, 0); | |
157 | if (retval > 0) { | |
158 | value = kmalloc(retval, GFP_KERNEL); | |
159 | if (!value) | |
160 | return ERR_PTR(-ENOMEM); | |
161 | retval = ext2_xattr_get(inode, name_index, "", value, retval); | |
162 | } | |
163 | if (retval > 0) | |
164 | acl = ext2_acl_from_disk(value, retval); | |
165 | else if (retval == -ENODATA || retval == -ENOSYS) | |
166 | acl = NULL; | |
167 | else | |
168 | acl = ERR_PTR(retval); | |
f99d49ad | 169 | kfree(value); |
1da177e4 | 170 | |
073aaa1b AV |
171 | if (!IS_ERR(acl)) |
172 | set_cached_acl(inode, type, acl); | |
1da177e4 | 173 | |
1da177e4 LT |
174 | return acl; |
175 | } | |
176 | ||
177 | /* | |
1b1dcc1b | 178 | * inode->i_mutex: down |
1da177e4 LT |
179 | */ |
180 | static int | |
181 | ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
182 | { | |
1da177e4 LT |
183 | int name_index; |
184 | void *value = NULL; | |
dfa08592 | 185 | size_t size = 0; |
1da177e4 LT |
186 | int error; |
187 | ||
188 | if (S_ISLNK(inode->i_mode)) | |
189 | return -EOPNOTSUPP; | |
190 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
191 | return 0; | |
192 | ||
193 | switch(type) { | |
194 | case ACL_TYPE_ACCESS: | |
195 | name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS; | |
196 | if (acl) { | |
d6952123 | 197 | error = posix_acl_equiv_mode(acl, &inode->i_mode); |
1da177e4 LT |
198 | if (error < 0) |
199 | return error; | |
200 | else { | |
523825bc | 201 | inode->i_ctime = CURRENT_TIME_SEC; |
1da177e4 LT |
202 | mark_inode_dirty(inode); |
203 | if (error == 0) | |
204 | acl = NULL; | |
205 | } | |
206 | } | |
207 | break; | |
208 | ||
209 | case ACL_TYPE_DEFAULT: | |
210 | name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
211 | if (!S_ISDIR(inode->i_mode)) | |
212 | return acl ? -EACCES : 0; | |
213 | break; | |
214 | ||
215 | default: | |
216 | return -EINVAL; | |
217 | } | |
218 | if (acl) { | |
219 | value = ext2_acl_to_disk(acl, &size); | |
220 | if (IS_ERR(value)) | |
221 | return (int)PTR_ERR(value); | |
222 | } | |
223 | ||
224 | error = ext2_xattr_set(inode, name_index, "", value, size, 0); | |
225 | ||
f99d49ad | 226 | kfree(value); |
073aaa1b AV |
227 | if (!error) |
228 | set_cached_acl(inode, type, acl); | |
1da177e4 LT |
229 | return error; |
230 | } | |
231 | ||
1da177e4 LT |
232 | /* |
233 | * Initialize the ACLs of a new inode. Called from ext2_new_inode. | |
234 | * | |
1b1dcc1b JS |
235 | * dir->i_mutex: down |
236 | * inode->i_mutex: up (access to inode is still exclusive) | |
1da177e4 LT |
237 | */ |
238 | int | |
239 | ext2_init_acl(struct inode *inode, struct inode *dir) | |
240 | { | |
241 | struct posix_acl *acl = NULL; | |
242 | int error = 0; | |
243 | ||
244 | if (!S_ISLNK(inode->i_mode)) { | |
245 | if (test_opt(dir->i_sb, POSIX_ACL)) { | |
246 | acl = ext2_get_acl(dir, ACL_TYPE_DEFAULT); | |
247 | if (IS_ERR(acl)) | |
248 | return PTR_ERR(acl); | |
249 | } | |
250 | if (!acl) | |
ce3b0f8d | 251 | inode->i_mode &= ~current_umask(); |
1da177e4 LT |
252 | } |
253 | if (test_opt(inode->i_sb, POSIX_ACL) && acl) { | |
1da177e4 LT |
254 | if (S_ISDIR(inode->i_mode)) { |
255 | error = ext2_set_acl(inode, ACL_TYPE_DEFAULT, acl); | |
256 | if (error) | |
257 | goto cleanup; | |
258 | } | |
d3fb6120 | 259 | error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode); |
826cae2f AV |
260 | if (error < 0) |
261 | return error; | |
826cae2f AV |
262 | if (error > 0) { |
263 | /* This is an extended ACL */ | |
264 | error = ext2_set_acl(inode, ACL_TYPE_ACCESS, acl); | |
1da177e4 | 265 | } |
1da177e4 LT |
266 | } |
267 | cleanup: | |
268 | posix_acl_release(acl); | |
269 | return error; | |
270 | } | |
271 | ||
272 | /* | |
273 | * Does chmod for an inode that may have an Access Control List. The | |
274 | * inode->i_mode field must be updated to the desired value by the caller | |
275 | * before calling this function. | |
276 | * Returns 0 on success, or a negative error number. | |
277 | * | |
278 | * We change the ACL rather than storing some ACL entries in the file | |
279 | * mode permission bits (which would be more efficient), because that | |
280 | * would break once additional permissions (like ACL_APPEND, ACL_DELETE | |
281 | * for directories) are added. There are no more bits available in the | |
282 | * file mode. | |
283 | * | |
1b1dcc1b | 284 | * inode->i_mutex: down |
1da177e4 LT |
285 | */ |
286 | int | |
287 | ext2_acl_chmod(struct inode *inode) | |
288 | { | |
bc26ab5f | 289 | struct posix_acl *acl; |
1da177e4 LT |
290 | int error; |
291 | ||
292 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
293 | return 0; | |
294 | if (S_ISLNK(inode->i_mode)) | |
295 | return -EOPNOTSUPP; | |
296 | acl = ext2_get_acl(inode, ACL_TYPE_ACCESS); | |
297 | if (IS_ERR(acl) || !acl) | |
298 | return PTR_ERR(acl); | |
bc26ab5f AV |
299 | error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); |
300 | if (error) | |
301 | return error; | |
302 | error = ext2_set_acl(inode, ACL_TYPE_ACCESS, acl); | |
1da177e4 | 303 | posix_acl_release(acl); |
1da177e4 LT |
304 | return error; |
305 | } | |
306 | ||
307 | /* | |
308 | * Extended attribut handlers | |
309 | */ | |
310 | static size_t | |
431547b3 CH |
311 | ext2_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_size, |
312 | const char *name, size_t name_len, int type) | |
1da177e4 | 313 | { |
9a59f452 | 314 | const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); |
1da177e4 | 315 | |
431547b3 | 316 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
1da177e4 LT |
317 | return 0; |
318 | if (list && size <= list_size) | |
9a59f452 | 319 | memcpy(list, POSIX_ACL_XATTR_ACCESS, size); |
1da177e4 LT |
320 | return size; |
321 | } | |
322 | ||
323 | static size_t | |
431547b3 CH |
324 | ext2_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_size, |
325 | const char *name, size_t name_len, int type) | |
1da177e4 | 326 | { |
9a59f452 | 327 | const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); |
1da177e4 | 328 | |
431547b3 | 329 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
1da177e4 LT |
330 | return 0; |
331 | if (list && size <= list_size) | |
9a59f452 | 332 | memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); |
1da177e4 LT |
333 | return size; |
334 | } | |
335 | ||
336 | static int | |
431547b3 CH |
337 | ext2_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer, |
338 | size_t size, int type) | |
1da177e4 LT |
339 | { |
340 | struct posix_acl *acl; | |
341 | int error; | |
342 | ||
431547b3 CH |
343 | if (strcmp(name, "") != 0) |
344 | return -EINVAL; | |
345 | if (!test_opt(dentry->d_sb, POSIX_ACL)) | |
1da177e4 LT |
346 | return -EOPNOTSUPP; |
347 | ||
431547b3 | 348 | acl = ext2_get_acl(dentry->d_inode, type); |
1da177e4 LT |
349 | if (IS_ERR(acl)) |
350 | return PTR_ERR(acl); | |
351 | if (acl == NULL) | |
352 | return -ENODATA; | |
353 | error = posix_acl_to_xattr(acl, buffer, size); | |
354 | posix_acl_release(acl); | |
355 | ||
356 | return error; | |
357 | } | |
358 | ||
359 | static int | |
431547b3 CH |
360 | ext2_xattr_set_acl(struct dentry *dentry, const char *name, const void *value, |
361 | size_t size, int flags, int type) | |
1da177e4 LT |
362 | { |
363 | struct posix_acl *acl; | |
364 | int error; | |
365 | ||
431547b3 CH |
366 | if (strcmp(name, "") != 0) |
367 | return -EINVAL; | |
368 | if (!test_opt(dentry->d_sb, POSIX_ACL)) | |
1da177e4 | 369 | return -EOPNOTSUPP; |
2e149670 | 370 | if (!inode_owner_or_capable(dentry->d_inode)) |
1da177e4 LT |
371 | return -EPERM; |
372 | ||
373 | if (value) { | |
374 | acl = posix_acl_from_xattr(value, size); | |
375 | if (IS_ERR(acl)) | |
376 | return PTR_ERR(acl); | |
377 | else if (acl) { | |
378 | error = posix_acl_valid(acl); | |
379 | if (error) | |
380 | goto release_and_out; | |
381 | } | |
382 | } else | |
383 | acl = NULL; | |
384 | ||
431547b3 | 385 | error = ext2_set_acl(dentry->d_inode, type, acl); |
1da177e4 LT |
386 | |
387 | release_and_out: | |
388 | posix_acl_release(acl); | |
389 | return error; | |
390 | } | |
391 | ||
749c72ef | 392 | const struct xattr_handler ext2_xattr_acl_access_handler = { |
9a59f452 | 393 | .prefix = POSIX_ACL_XATTR_ACCESS, |
431547b3 | 394 | .flags = ACL_TYPE_ACCESS, |
1da177e4 | 395 | .list = ext2_xattr_list_acl_access, |
431547b3 CH |
396 | .get = ext2_xattr_get_acl, |
397 | .set = ext2_xattr_set_acl, | |
1da177e4 LT |
398 | }; |
399 | ||
749c72ef | 400 | const struct xattr_handler ext2_xattr_acl_default_handler = { |
9a59f452 | 401 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
431547b3 | 402 | .flags = ACL_TYPE_DEFAULT, |
1da177e4 | 403 | .list = ext2_xattr_list_acl_default, |
431547b3 CH |
404 | .get = ext2_xattr_get_acl, |
405 | .set = ext2_xattr_set_acl, | |
1da177e4 | 406 | }; |