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Commit | Line | Data |
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652ecc20 KK |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
aa98d7cf | 3 | * |
c00c310e | 4 | * Copyright © 2006 NEC Corporation |
aa98d7cf | 5 | * |
652ecc20 KK |
6 | * Created by KaiGai Kohei <kaigai@ak.jp.nec.com> |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
10 | */ | |
c00c310e | 11 | |
aa98d7cf KK |
12 | #include <linux/kernel.h> |
13 | #include <linux/slab.h> | |
14 | #include <linux/fs.h> | |
914e2637 | 15 | #include <linux/sched.h> |
aa98d7cf KK |
16 | #include <linux/time.h> |
17 | #include <linux/crc32.h> | |
18 | #include <linux/jffs2.h> | |
19 | #include <linux/xattr.h> | |
20 | #include <linux/posix_acl_xattr.h> | |
21 | #include <linux/mtd/mtd.h> | |
22 | #include "nodelist.h" | |
23 | ||
24 | static size_t jffs2_acl_size(int count) | |
25 | { | |
26 | if (count <= 4) { | |
de1f72fa KK |
27 | return sizeof(struct jffs2_acl_header) |
28 | + count * sizeof(struct jffs2_acl_entry_short); | |
aa98d7cf | 29 | } else { |
de1f72fa KK |
30 | return sizeof(struct jffs2_acl_header) |
31 | + 4 * sizeof(struct jffs2_acl_entry_short) | |
32 | + (count - 4) * sizeof(struct jffs2_acl_entry); | |
aa98d7cf KK |
33 | } |
34 | } | |
35 | ||
36 | static int jffs2_acl_count(size_t size) | |
37 | { | |
38 | size_t s; | |
39 | ||
de1f72fa KK |
40 | size -= sizeof(struct jffs2_acl_header); |
41 | s = size - 4 * sizeof(struct jffs2_acl_entry_short); | |
aa98d7cf | 42 | if (s < 0) { |
de1f72fa | 43 | if (size % sizeof(struct jffs2_acl_entry_short)) |
aa98d7cf | 44 | return -1; |
de1f72fa | 45 | return size / sizeof(struct jffs2_acl_entry_short); |
aa98d7cf | 46 | } else { |
de1f72fa | 47 | if (s % sizeof(struct jffs2_acl_entry)) |
aa98d7cf | 48 | return -1; |
de1f72fa | 49 | return s / sizeof(struct jffs2_acl_entry) + 4; |
aa98d7cf KK |
50 | } |
51 | } | |
52 | ||
dea80134 | 53 | static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size) |
aa98d7cf | 54 | { |
dea80134 KK |
55 | void *end = value + size; |
56 | struct jffs2_acl_header *header = value; | |
57 | struct jffs2_acl_entry *entry; | |
aa98d7cf KK |
58 | struct posix_acl *acl; |
59 | uint32_t ver; | |
60 | int i, count; | |
61 | ||
62 | if (!value) | |
63 | return NULL; | |
de1f72fa | 64 | if (size < sizeof(struct jffs2_acl_header)) |
aa98d7cf | 65 | return ERR_PTR(-EINVAL); |
dea80134 | 66 | ver = je32_to_cpu(header->a_version); |
aa98d7cf KK |
67 | if (ver != JFFS2_ACL_VERSION) { |
68 | JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver); | |
69 | return ERR_PTR(-EINVAL); | |
70 | } | |
71 | ||
dea80134 | 72 | value += sizeof(struct jffs2_acl_header); |
aa98d7cf KK |
73 | count = jffs2_acl_count(size); |
74 | if (count < 0) | |
75 | return ERR_PTR(-EINVAL); | |
76 | if (count == 0) | |
77 | return NULL; | |
78 | ||
79 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
80 | if (!acl) | |
81 | return ERR_PTR(-ENOMEM); | |
82 | ||
83 | for (i=0; i < count; i++) { | |
dea80134 KK |
84 | entry = value; |
85 | if (value + sizeof(struct jffs2_acl_entry_short) > end) | |
aa98d7cf KK |
86 | goto fail; |
87 | acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag); | |
88 | acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm); | |
89 | switch (acl->a_entries[i].e_tag) { | |
90 | case ACL_USER_OBJ: | |
91 | case ACL_GROUP_OBJ: | |
92 | case ACL_MASK: | |
93 | case ACL_OTHER: | |
dea80134 | 94 | value += sizeof(struct jffs2_acl_entry_short); |
aa98d7cf KK |
95 | acl->a_entries[i].e_id = ACL_UNDEFINED_ID; |
96 | break; | |
97 | ||
98 | case ACL_USER: | |
99 | case ACL_GROUP: | |
dea80134 KK |
100 | value += sizeof(struct jffs2_acl_entry); |
101 | if (value > end) | |
aa98d7cf KK |
102 | goto fail; |
103 | acl->a_entries[i].e_id = je32_to_cpu(entry->e_id); | |
104 | break; | |
105 | ||
106 | default: | |
107 | goto fail; | |
108 | } | |
109 | } | |
110 | if (value != end) | |
111 | goto fail; | |
112 | return acl; | |
113 | fail: | |
114 | posix_acl_release(acl); | |
115 | return ERR_PTR(-EINVAL); | |
116 | } | |
117 | ||
118 | static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size) | |
119 | { | |
dea80134 KK |
120 | struct jffs2_acl_header *header; |
121 | struct jffs2_acl_entry *entry; | |
122 | void *e; | |
aa98d7cf KK |
123 | size_t i; |
124 | ||
125 | *size = jffs2_acl_size(acl->a_count); | |
dea80134 KK |
126 | header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL); |
127 | if (!header) | |
aa98d7cf | 128 | return ERR_PTR(-ENOMEM); |
dea80134 KK |
129 | header->a_version = cpu_to_je32(JFFS2_ACL_VERSION); |
130 | e = header + 1; | |
aa98d7cf | 131 | for (i=0; i < acl->a_count; i++) { |
dea80134 | 132 | entry = e; |
aa98d7cf KK |
133 | entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag); |
134 | entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm); | |
135 | switch(acl->a_entries[i].e_tag) { | |
136 | case ACL_USER: | |
137 | case ACL_GROUP: | |
138 | entry->e_id = cpu_to_je32(acl->a_entries[i].e_id); | |
de1f72fa | 139 | e += sizeof(struct jffs2_acl_entry); |
aa98d7cf KK |
140 | break; |
141 | ||
142 | case ACL_USER_OBJ: | |
143 | case ACL_GROUP_OBJ: | |
144 | case ACL_MASK: | |
145 | case ACL_OTHER: | |
de1f72fa | 146 | e += sizeof(struct jffs2_acl_entry_short); |
aa98d7cf KK |
147 | break; |
148 | ||
149 | default: | |
150 | goto fail; | |
151 | } | |
152 | } | |
dea80134 | 153 | return header; |
aa98d7cf | 154 | fail: |
dea80134 | 155 | kfree(header); |
aa98d7cf KK |
156 | return ERR_PTR(-EINVAL); |
157 | } | |
158 | ||
159 | static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl) | |
160 | { | |
161 | struct posix_acl *acl = JFFS2_ACL_NOT_CACHED; | |
162 | ||
163 | spin_lock(&inode->i_lock); | |
164 | if (*i_acl != JFFS2_ACL_NOT_CACHED) | |
165 | acl = posix_acl_dup(*i_acl); | |
166 | spin_unlock(&inode->i_lock); | |
167 | return acl; | |
168 | } | |
169 | ||
170 | static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl) | |
171 | { | |
172 | spin_lock(&inode->i_lock); | |
173 | if (*i_acl != JFFS2_ACL_NOT_CACHED) | |
174 | posix_acl_release(*i_acl); | |
175 | *i_acl = posix_acl_dup(acl); | |
176 | spin_unlock(&inode->i_lock); | |
177 | } | |
178 | ||
050416e9 | 179 | static struct posix_acl *jffs2_get_acl(struct inode *inode, int type) |
aa98d7cf KK |
180 | { |
181 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
182 | struct posix_acl *acl; | |
183 | char *value = NULL; | |
184 | int rc, xprefix; | |
185 | ||
186 | switch (type) { | |
187 | case ACL_TYPE_ACCESS: | |
188 | acl = jffs2_iget_acl(inode, &f->i_acl_access); | |
189 | if (acl != JFFS2_ACL_NOT_CACHED) | |
190 | return acl; | |
191 | xprefix = JFFS2_XPREFIX_ACL_ACCESS; | |
192 | break; | |
193 | case ACL_TYPE_DEFAULT: | |
194 | acl = jffs2_iget_acl(inode, &f->i_acl_default); | |
195 | if (acl != JFFS2_ACL_NOT_CACHED) | |
196 | return acl; | |
197 | xprefix = JFFS2_XPREFIX_ACL_DEFAULT; | |
198 | break; | |
199 | default: | |
200 | return ERR_PTR(-EINVAL); | |
201 | } | |
202 | rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0); | |
203 | if (rc > 0) { | |
204 | value = kmalloc(rc, GFP_KERNEL); | |
205 | if (!value) | |
206 | return ERR_PTR(-ENOMEM); | |
207 | rc = do_jffs2_getxattr(inode, xprefix, "", value, rc); | |
208 | } | |
209 | if (rc > 0) { | |
210 | acl = jffs2_acl_from_medium(value, rc); | |
211 | } else if (rc == -ENODATA || rc == -ENOSYS) { | |
212 | acl = NULL; | |
213 | } else { | |
214 | acl = ERR_PTR(rc); | |
215 | } | |
216 | if (value) | |
217 | kfree(value); | |
218 | if (!IS_ERR(acl)) { | |
219 | switch (type) { | |
220 | case ACL_TYPE_ACCESS: | |
221 | jffs2_iset_acl(inode, &f->i_acl_access, acl); | |
222 | break; | |
223 | case ACL_TYPE_DEFAULT: | |
224 | jffs2_iset_acl(inode, &f->i_acl_default, acl); | |
225 | break; | |
226 | } | |
227 | } | |
228 | return acl; | |
229 | } | |
230 | ||
cfc8dc6f KK |
231 | static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl) |
232 | { | |
233 | char *value = NULL; | |
234 | size_t size = 0; | |
235 | int rc; | |
236 | ||
237 | if (acl) { | |
238 | value = jffs2_acl_to_medium(acl, &size); | |
239 | if (IS_ERR(value)) | |
240 | return PTR_ERR(value); | |
241 | } | |
242 | rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0); | |
243 | if (!value && rc == -ENODATA) | |
244 | rc = 0; | |
245 | kfree(value); | |
246 | ||
247 | return rc; | |
248 | } | |
249 | ||
aa98d7cf KK |
250 | static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl) |
251 | { | |
252 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
aa98d7cf KK |
253 | int rc, xprefix; |
254 | ||
255 | if (S_ISLNK(inode->i_mode)) | |
256 | return -EOPNOTSUPP; | |
257 | ||
258 | switch (type) { | |
259 | case ACL_TYPE_ACCESS: | |
260 | xprefix = JFFS2_XPREFIX_ACL_ACCESS; | |
261 | if (acl) { | |
262 | mode_t mode = inode->i_mode; | |
263 | rc = posix_acl_equiv_mode(acl, &mode); | |
264 | if (rc < 0) | |
265 | return rc; | |
266 | if (inode->i_mode != mode) { | |
9ed437c5 DW |
267 | struct iattr attr; |
268 | ||
269 | attr.ia_valid = ATTR_MODE; | |
270 | attr.ia_mode = mode; | |
271 | rc = jffs2_do_setattr(inode, &attr); | |
272 | if (rc < 0) | |
273 | return rc; | |
aa98d7cf KK |
274 | } |
275 | if (rc == 0) | |
276 | acl = NULL; | |
277 | } | |
278 | break; | |
279 | case ACL_TYPE_DEFAULT: | |
280 | xprefix = JFFS2_XPREFIX_ACL_DEFAULT; | |
281 | if (!S_ISDIR(inode->i_mode)) | |
282 | return acl ? -EACCES : 0; | |
283 | break; | |
284 | default: | |
285 | return -EINVAL; | |
286 | } | |
cfc8dc6f | 287 | rc = __jffs2_set_acl(inode, xprefix, acl); |
aa98d7cf KK |
288 | if (!rc) { |
289 | switch(type) { | |
290 | case ACL_TYPE_ACCESS: | |
291 | jffs2_iset_acl(inode, &f->i_acl_access, acl); | |
292 | break; | |
293 | case ACL_TYPE_DEFAULT: | |
294 | jffs2_iset_acl(inode, &f->i_acl_default, acl); | |
295 | break; | |
296 | } | |
297 | } | |
298 | return rc; | |
299 | } | |
300 | ||
301 | static int jffs2_check_acl(struct inode *inode, int mask) | |
302 | { | |
303 | struct posix_acl *acl; | |
304 | int rc; | |
305 | ||
306 | acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); | |
307 | if (IS_ERR(acl)) | |
308 | return PTR_ERR(acl); | |
309 | if (acl) { | |
310 | rc = posix_acl_permission(inode, acl, mask); | |
311 | posix_acl_release(acl); | |
312 | return rc; | |
313 | } | |
314 | return -EAGAIN; | |
315 | } | |
316 | ||
317 | int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd) | |
318 | { | |
319 | return generic_permission(inode, mask, jffs2_check_acl); | |
320 | } | |
321 | ||
cfc8dc6f | 322 | int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode) |
aa98d7cf KK |
323 | { |
324 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
cfc8dc6f KK |
325 | struct posix_acl *acl, *clone; |
326 | int rc; | |
aa98d7cf | 327 | |
cfc8dc6f KK |
328 | f->i_acl_default = NULL; |
329 | f->i_acl_access = NULL; | |
330 | ||
331 | if (S_ISLNK(*i_mode)) | |
332 | return 0; /* Symlink always has no-ACL */ | |
333 | ||
334 | acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT); | |
335 | if (IS_ERR(acl)) | |
336 | return PTR_ERR(acl); | |
337 | ||
338 | if (!acl) { | |
339 | *i_mode &= ~current->fs->umask; | |
340 | } else { | |
341 | if (S_ISDIR(*i_mode)) | |
342 | jffs2_iset_acl(inode, &f->i_acl_default, acl); | |
9ed437c5 | 343 | |
aa98d7cf | 344 | clone = posix_acl_clone(acl, GFP_KERNEL); |
aa98d7cf | 345 | if (!clone) |
cfc8dc6f KK |
346 | return -ENOMEM; |
347 | rc = posix_acl_create_masq(clone, (mode_t *)i_mode); | |
36f97bc6 JL |
348 | if (rc < 0) { |
349 | posix_acl_release(clone); | |
cfc8dc6f | 350 | return rc; |
36f97bc6 | 351 | } |
cfc8dc6f KK |
352 | if (rc > 0) |
353 | jffs2_iset_acl(inode, &f->i_acl_access, clone); | |
354 | ||
aa98d7cf KK |
355 | posix_acl_release(clone); |
356 | } | |
cfc8dc6f KK |
357 | return 0; |
358 | } | |
359 | ||
360 | int jffs2_init_acl_post(struct inode *inode) | |
361 | { | |
362 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
363 | int rc; | |
364 | ||
365 | if (f->i_acl_default) { | |
366 | rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, f->i_acl_default); | |
367 | if (rc) | |
368 | return rc; | |
369 | } | |
370 | ||
371 | if (f->i_acl_access) { | |
372 | rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, f->i_acl_access); | |
373 | if (rc) | |
374 | return rc; | |
375 | } | |
376 | ||
8d6ea587 | 377 | return 0; |
aa98d7cf KK |
378 | } |
379 | ||
c7afb0f9 | 380 | void jffs2_clear_acl(struct jffs2_inode_info *f) |
aa98d7cf | 381 | { |
aa98d7cf KK |
382 | if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) { |
383 | posix_acl_release(f->i_acl_access); | |
384 | f->i_acl_access = JFFS2_ACL_NOT_CACHED; | |
385 | } | |
386 | if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) { | |
387 | posix_acl_release(f->i_acl_default); | |
388 | f->i_acl_default = JFFS2_ACL_NOT_CACHED; | |
389 | } | |
390 | } | |
391 | ||
392 | int jffs2_acl_chmod(struct inode *inode) | |
393 | { | |
394 | struct posix_acl *acl, *clone; | |
395 | int rc; | |
396 | ||
397 | if (S_ISLNK(inode->i_mode)) | |
398 | return -EOPNOTSUPP; | |
399 | acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); | |
400 | if (IS_ERR(acl) || !acl) | |
401 | return PTR_ERR(acl); | |
402 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
403 | posix_acl_release(acl); | |
404 | if (!clone) | |
405 | return -ENOMEM; | |
406 | rc = posix_acl_chmod_masq(clone, inode->i_mode); | |
407 | if (!rc) | |
408 | rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
409 | posix_acl_release(clone); | |
410 | return rc; | |
411 | } | |
412 | ||
413 | static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size, | |
414 | const char *name, size_t name_len) | |
415 | { | |
416 | const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS); | |
417 | ||
418 | if (list && retlen <= list_size) | |
419 | strcpy(list, POSIX_ACL_XATTR_ACCESS); | |
420 | return retlen; | |
421 | } | |
422 | ||
423 | static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size, | |
424 | const char *name, size_t name_len) | |
425 | { | |
426 | const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT); | |
427 | ||
428 | if (list && retlen <= list_size) | |
429 | strcpy(list, POSIX_ACL_XATTR_DEFAULT); | |
430 | return retlen; | |
431 | } | |
432 | ||
433 | static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size) | |
434 | { | |
435 | struct posix_acl *acl; | |
436 | int rc; | |
437 | ||
438 | acl = jffs2_get_acl(inode, type); | |
439 | if (IS_ERR(acl)) | |
440 | return PTR_ERR(acl); | |
441 | if (!acl) | |
442 | return -ENODATA; | |
443 | rc = posix_acl_to_xattr(acl, buffer, size); | |
444 | posix_acl_release(acl); | |
445 | ||
446 | return rc; | |
447 | } | |
448 | ||
449 | static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size) | |
450 | { | |
451 | if (name[0] != '\0') | |
452 | return -EINVAL; | |
453 | return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size); | |
454 | } | |
455 | ||
456 | static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size) | |
457 | { | |
458 | if (name[0] != '\0') | |
459 | return -EINVAL; | |
460 | return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size); | |
461 | } | |
462 | ||
463 | static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size) | |
464 | { | |
465 | struct posix_acl *acl; | |
466 | int rc; | |
467 | ||
3bd858ab | 468 | if (!is_owner_or_cap(inode)) |
aa98d7cf KK |
469 | return -EPERM; |
470 | ||
471 | if (value) { | |
472 | acl = posix_acl_from_xattr(value, size); | |
473 | if (IS_ERR(acl)) | |
474 | return PTR_ERR(acl); | |
475 | if (acl) { | |
476 | rc = posix_acl_valid(acl); | |
477 | if (rc) | |
478 | goto out; | |
479 | } | |
480 | } else { | |
481 | acl = NULL; | |
482 | } | |
483 | rc = jffs2_set_acl(inode, type, acl); | |
484 | out: | |
485 | posix_acl_release(acl); | |
486 | return rc; | |
487 | } | |
488 | ||
489 | static int jffs2_acl_access_setxattr(struct inode *inode, const char *name, | |
490 | const void *buffer, size_t size, int flags) | |
491 | { | |
492 | if (name[0] != '\0') | |
493 | return -EINVAL; | |
494 | return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size); | |
495 | } | |
496 | ||
497 | static int jffs2_acl_default_setxattr(struct inode *inode, const char *name, | |
498 | const void *buffer, size_t size, int flags) | |
499 | { | |
500 | if (name[0] != '\0') | |
501 | return -EINVAL; | |
502 | return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size); | |
503 | } | |
504 | ||
505 | struct xattr_handler jffs2_acl_access_xattr_handler = { | |
506 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
507 | .list = jffs2_acl_access_listxattr, | |
508 | .get = jffs2_acl_access_getxattr, | |
509 | .set = jffs2_acl_access_setxattr, | |
510 | }; | |
511 | ||
512 | struct xattr_handler jffs2_acl_default_xattr_handler = { | |
513 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
514 | .list = jffs2_acl_default_listxattr, | |
515 | .get = jffs2_acl_default_getxattr, | |
516 | .set = jffs2_acl_default_setxattr, | |
517 | }; |