Commit | Line | Data |
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652ecc20 KK |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
aa98d7cf | 3 | * |
652ecc20 | 4 | * Copyright (C) 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 | */ | |
aa98d7cf KK |
11 | #include <linux/kernel.h> |
12 | #include <linux/slab.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/time.h> | |
15 | #include <linux/crc32.h> | |
16 | #include <linux/jffs2.h> | |
17 | #include <linux/xattr.h> | |
18 | #include <linux/posix_acl_xattr.h> | |
19 | #include <linux/mtd/mtd.h> | |
20 | #include "nodelist.h" | |
21 | ||
22 | static size_t jffs2_acl_size(int count) | |
23 | { | |
24 | if (count <= 4) { | |
de1f72fa KK |
25 | return sizeof(struct jffs2_acl_header) |
26 | + count * sizeof(struct jffs2_acl_entry_short); | |
aa98d7cf | 27 | } else { |
de1f72fa KK |
28 | return sizeof(struct jffs2_acl_header) |
29 | + 4 * sizeof(struct jffs2_acl_entry_short) | |
30 | + (count - 4) * sizeof(struct jffs2_acl_entry); | |
aa98d7cf KK |
31 | } |
32 | } | |
33 | ||
34 | static int jffs2_acl_count(size_t size) | |
35 | { | |
36 | size_t s; | |
37 | ||
de1f72fa KK |
38 | size -= sizeof(struct jffs2_acl_header); |
39 | s = size - 4 * sizeof(struct jffs2_acl_entry_short); | |
aa98d7cf | 40 | if (s < 0) { |
de1f72fa | 41 | if (size % sizeof(struct jffs2_acl_entry_short)) |
aa98d7cf | 42 | return -1; |
de1f72fa | 43 | return size / sizeof(struct jffs2_acl_entry_short); |
aa98d7cf | 44 | } else { |
de1f72fa | 45 | if (s % sizeof(struct jffs2_acl_entry)) |
aa98d7cf | 46 | return -1; |
de1f72fa | 47 | return s / sizeof(struct jffs2_acl_entry) + 4; |
aa98d7cf KK |
48 | } |
49 | } | |
50 | ||
dea80134 | 51 | static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size) |
aa98d7cf | 52 | { |
dea80134 KK |
53 | void *end = value + size; |
54 | struct jffs2_acl_header *header = value; | |
55 | struct jffs2_acl_entry *entry; | |
aa98d7cf KK |
56 | struct posix_acl *acl; |
57 | uint32_t ver; | |
58 | int i, count; | |
59 | ||
60 | if (!value) | |
61 | return NULL; | |
de1f72fa | 62 | if (size < sizeof(struct jffs2_acl_header)) |
aa98d7cf | 63 | return ERR_PTR(-EINVAL); |
dea80134 | 64 | ver = je32_to_cpu(header->a_version); |
aa98d7cf KK |
65 | if (ver != JFFS2_ACL_VERSION) { |
66 | JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver); | |
67 | return ERR_PTR(-EINVAL); | |
68 | } | |
69 | ||
dea80134 | 70 | value += sizeof(struct jffs2_acl_header); |
aa98d7cf KK |
71 | count = jffs2_acl_count(size); |
72 | if (count < 0) | |
73 | return ERR_PTR(-EINVAL); | |
74 | if (count == 0) | |
75 | return NULL; | |
76 | ||
77 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
78 | if (!acl) | |
79 | return ERR_PTR(-ENOMEM); | |
80 | ||
81 | for (i=0; i < count; i++) { | |
dea80134 KK |
82 | entry = value; |
83 | if (value + sizeof(struct jffs2_acl_entry_short) > end) | |
aa98d7cf KK |
84 | goto fail; |
85 | acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag); | |
86 | acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm); | |
87 | switch (acl->a_entries[i].e_tag) { | |
88 | case ACL_USER_OBJ: | |
89 | case ACL_GROUP_OBJ: | |
90 | case ACL_MASK: | |
91 | case ACL_OTHER: | |
dea80134 | 92 | value += sizeof(struct jffs2_acl_entry_short); |
aa98d7cf KK |
93 | acl->a_entries[i].e_id = ACL_UNDEFINED_ID; |
94 | break; | |
95 | ||
96 | case ACL_USER: | |
97 | case ACL_GROUP: | |
dea80134 KK |
98 | value += sizeof(struct jffs2_acl_entry); |
99 | if (value > end) | |
aa98d7cf KK |
100 | goto fail; |
101 | acl->a_entries[i].e_id = je32_to_cpu(entry->e_id); | |
102 | break; | |
103 | ||
104 | default: | |
105 | goto fail; | |
106 | } | |
107 | } | |
108 | if (value != end) | |
109 | goto fail; | |
110 | return acl; | |
111 | fail: | |
112 | posix_acl_release(acl); | |
113 | return ERR_PTR(-EINVAL); | |
114 | } | |
115 | ||
116 | static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size) | |
117 | { | |
dea80134 KK |
118 | struct jffs2_acl_header *header; |
119 | struct jffs2_acl_entry *entry; | |
120 | void *e; | |
aa98d7cf KK |
121 | size_t i; |
122 | ||
123 | *size = jffs2_acl_size(acl->a_count); | |
dea80134 KK |
124 | header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL); |
125 | if (!header) | |
aa98d7cf | 126 | return ERR_PTR(-ENOMEM); |
dea80134 KK |
127 | header->a_version = cpu_to_je32(JFFS2_ACL_VERSION); |
128 | e = header + 1; | |
aa98d7cf | 129 | for (i=0; i < acl->a_count; i++) { |
dea80134 | 130 | entry = e; |
aa98d7cf KK |
131 | entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag); |
132 | entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm); | |
133 | switch(acl->a_entries[i].e_tag) { | |
134 | case ACL_USER: | |
135 | case ACL_GROUP: | |
136 | entry->e_id = cpu_to_je32(acl->a_entries[i].e_id); | |
de1f72fa | 137 | e += sizeof(struct jffs2_acl_entry); |
aa98d7cf KK |
138 | break; |
139 | ||
140 | case ACL_USER_OBJ: | |
141 | case ACL_GROUP_OBJ: | |
142 | case ACL_MASK: | |
143 | case ACL_OTHER: | |
de1f72fa | 144 | e += sizeof(struct jffs2_acl_entry_short); |
aa98d7cf KK |
145 | break; |
146 | ||
147 | default: | |
148 | goto fail; | |
149 | } | |
150 | } | |
dea80134 | 151 | return header; |
aa98d7cf | 152 | fail: |
dea80134 | 153 | kfree(header); |
aa98d7cf KK |
154 | return ERR_PTR(-EINVAL); |
155 | } | |
156 | ||
157 | static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl) | |
158 | { | |
159 | struct posix_acl *acl = JFFS2_ACL_NOT_CACHED; | |
160 | ||
161 | spin_lock(&inode->i_lock); | |
162 | if (*i_acl != JFFS2_ACL_NOT_CACHED) | |
163 | acl = posix_acl_dup(*i_acl); | |
164 | spin_unlock(&inode->i_lock); | |
165 | return acl; | |
166 | } | |
167 | ||
168 | static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl) | |
169 | { | |
170 | spin_lock(&inode->i_lock); | |
171 | if (*i_acl != JFFS2_ACL_NOT_CACHED) | |
172 | posix_acl_release(*i_acl); | |
173 | *i_acl = posix_acl_dup(acl); | |
174 | spin_unlock(&inode->i_lock); | |
175 | } | |
176 | ||
177 | static struct posix_acl *jffs2_get_acl(struct inode *inode, int type) | |
178 | { | |
179 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
180 | struct posix_acl *acl; | |
181 | char *value = NULL; | |
182 | int rc, xprefix; | |
183 | ||
184 | switch (type) { | |
185 | case ACL_TYPE_ACCESS: | |
186 | acl = jffs2_iget_acl(inode, &f->i_acl_access); | |
187 | if (acl != JFFS2_ACL_NOT_CACHED) | |
188 | return acl; | |
189 | xprefix = JFFS2_XPREFIX_ACL_ACCESS; | |
190 | break; | |
191 | case ACL_TYPE_DEFAULT: | |
192 | acl = jffs2_iget_acl(inode, &f->i_acl_default); | |
193 | if (acl != JFFS2_ACL_NOT_CACHED) | |
194 | return acl; | |
195 | xprefix = JFFS2_XPREFIX_ACL_DEFAULT; | |
196 | break; | |
197 | default: | |
198 | return ERR_PTR(-EINVAL); | |
199 | } | |
200 | rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0); | |
201 | if (rc > 0) { | |
202 | value = kmalloc(rc, GFP_KERNEL); | |
203 | if (!value) | |
204 | return ERR_PTR(-ENOMEM); | |
205 | rc = do_jffs2_getxattr(inode, xprefix, "", value, rc); | |
206 | } | |
207 | if (rc > 0) { | |
208 | acl = jffs2_acl_from_medium(value, rc); | |
209 | } else if (rc == -ENODATA || rc == -ENOSYS) { | |
210 | acl = NULL; | |
211 | } else { | |
212 | acl = ERR_PTR(rc); | |
213 | } | |
214 | if (value) | |
215 | kfree(value); | |
216 | if (!IS_ERR(acl)) { | |
217 | switch (type) { | |
218 | case ACL_TYPE_ACCESS: | |
219 | jffs2_iset_acl(inode, &f->i_acl_access, acl); | |
220 | break; | |
221 | case ACL_TYPE_DEFAULT: | |
222 | jffs2_iset_acl(inode, &f->i_acl_default, acl); | |
223 | break; | |
224 | } | |
225 | } | |
226 | return acl; | |
227 | } | |
228 | ||
229 | static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
230 | { | |
231 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
232 | size_t size = 0; | |
233 | char *value = NULL; | |
234 | int rc, xprefix; | |
235 | ||
236 | if (S_ISLNK(inode->i_mode)) | |
237 | return -EOPNOTSUPP; | |
238 | ||
239 | switch (type) { | |
240 | case ACL_TYPE_ACCESS: | |
241 | xprefix = JFFS2_XPREFIX_ACL_ACCESS; | |
242 | if (acl) { | |
243 | mode_t mode = inode->i_mode; | |
244 | rc = posix_acl_equiv_mode(acl, &mode); | |
245 | if (rc < 0) | |
246 | return rc; | |
247 | if (inode->i_mode != mode) { | |
248 | inode->i_mode = mode; | |
249 | jffs2_dirty_inode(inode); | |
250 | } | |
251 | if (rc == 0) | |
252 | acl = NULL; | |
253 | } | |
254 | break; | |
255 | case ACL_TYPE_DEFAULT: | |
256 | xprefix = JFFS2_XPREFIX_ACL_DEFAULT; | |
257 | if (!S_ISDIR(inode->i_mode)) | |
258 | return acl ? -EACCES : 0; | |
259 | break; | |
260 | default: | |
261 | return -EINVAL; | |
262 | } | |
263 | if (acl) { | |
264 | value = jffs2_acl_to_medium(acl, &size); | |
265 | if (IS_ERR(value)) | |
266 | return PTR_ERR(value); | |
267 | } | |
268 | ||
269 | rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0); | |
a1ae76e9 KK |
270 | if (!value && rc == -ENODATA) |
271 | rc = 0; | |
aa98d7cf KK |
272 | if (value) |
273 | kfree(value); | |
274 | if (!rc) { | |
275 | switch(type) { | |
276 | case ACL_TYPE_ACCESS: | |
277 | jffs2_iset_acl(inode, &f->i_acl_access, acl); | |
278 | break; | |
279 | case ACL_TYPE_DEFAULT: | |
280 | jffs2_iset_acl(inode, &f->i_acl_default, acl); | |
281 | break; | |
282 | } | |
283 | } | |
284 | return rc; | |
285 | } | |
286 | ||
287 | static int jffs2_check_acl(struct inode *inode, int mask) | |
288 | { | |
289 | struct posix_acl *acl; | |
290 | int rc; | |
291 | ||
292 | acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); | |
293 | if (IS_ERR(acl)) | |
294 | return PTR_ERR(acl); | |
295 | if (acl) { | |
296 | rc = posix_acl_permission(inode, acl, mask); | |
297 | posix_acl_release(acl); | |
298 | return rc; | |
299 | } | |
300 | return -EAGAIN; | |
301 | } | |
302 | ||
303 | int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd) | |
304 | { | |
305 | return generic_permission(inode, mask, jffs2_check_acl); | |
306 | } | |
307 | ||
308 | int jffs2_init_acl(struct inode *inode, struct inode *dir) | |
309 | { | |
310 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
311 | struct posix_acl *acl = NULL, *clone; | |
312 | mode_t mode; | |
313 | int rc = 0; | |
314 | ||
315 | f->i_acl_access = JFFS2_ACL_NOT_CACHED; | |
316 | f->i_acl_default = JFFS2_ACL_NOT_CACHED; | |
317 | if (!S_ISLNK(inode->i_mode)) { | |
318 | acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT); | |
319 | if (IS_ERR(acl)) | |
320 | return PTR_ERR(acl); | |
321 | if (!acl) | |
322 | inode->i_mode &= ~current->fs->umask; | |
323 | } | |
324 | if (acl) { | |
325 | if (S_ISDIR(inode->i_mode)) { | |
326 | rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl); | |
327 | if (rc) | |
328 | goto cleanup; | |
329 | } | |
330 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
331 | rc = -ENOMEM; | |
332 | if (!clone) | |
333 | goto cleanup; | |
334 | mode = inode->i_mode; | |
335 | rc = posix_acl_create_masq(clone, &mode); | |
336 | if (rc >= 0) { | |
337 | inode->i_mode = mode; | |
338 | if (rc > 0) | |
339 | rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
340 | } | |
341 | posix_acl_release(clone); | |
342 | } | |
343 | cleanup: | |
344 | posix_acl_release(acl); | |
345 | return rc; | |
346 | } | |
347 | ||
c7afb0f9 | 348 | void jffs2_clear_acl(struct jffs2_inode_info *f) |
aa98d7cf | 349 | { |
aa98d7cf KK |
350 | if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) { |
351 | posix_acl_release(f->i_acl_access); | |
352 | f->i_acl_access = JFFS2_ACL_NOT_CACHED; | |
353 | } | |
354 | if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) { | |
355 | posix_acl_release(f->i_acl_default); | |
356 | f->i_acl_default = JFFS2_ACL_NOT_CACHED; | |
357 | } | |
358 | } | |
359 | ||
360 | int jffs2_acl_chmod(struct inode *inode) | |
361 | { | |
362 | struct posix_acl *acl, *clone; | |
363 | int rc; | |
364 | ||
365 | if (S_ISLNK(inode->i_mode)) | |
366 | return -EOPNOTSUPP; | |
367 | acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); | |
368 | if (IS_ERR(acl) || !acl) | |
369 | return PTR_ERR(acl); | |
370 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
371 | posix_acl_release(acl); | |
372 | if (!clone) | |
373 | return -ENOMEM; | |
374 | rc = posix_acl_chmod_masq(clone, inode->i_mode); | |
375 | if (!rc) | |
376 | rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone); | |
377 | posix_acl_release(clone); | |
378 | return rc; | |
379 | } | |
380 | ||
381 | static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size, | |
382 | const char *name, size_t name_len) | |
383 | { | |
384 | const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS); | |
385 | ||
386 | if (list && retlen <= list_size) | |
387 | strcpy(list, POSIX_ACL_XATTR_ACCESS); | |
388 | return retlen; | |
389 | } | |
390 | ||
391 | static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size, | |
392 | const char *name, size_t name_len) | |
393 | { | |
394 | const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT); | |
395 | ||
396 | if (list && retlen <= list_size) | |
397 | strcpy(list, POSIX_ACL_XATTR_DEFAULT); | |
398 | return retlen; | |
399 | } | |
400 | ||
401 | static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size) | |
402 | { | |
403 | struct posix_acl *acl; | |
404 | int rc; | |
405 | ||
406 | acl = jffs2_get_acl(inode, type); | |
407 | if (IS_ERR(acl)) | |
408 | return PTR_ERR(acl); | |
409 | if (!acl) | |
410 | return -ENODATA; | |
411 | rc = posix_acl_to_xattr(acl, buffer, size); | |
412 | posix_acl_release(acl); | |
413 | ||
414 | return rc; | |
415 | } | |
416 | ||
417 | static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size) | |
418 | { | |
419 | if (name[0] != '\0') | |
420 | return -EINVAL; | |
421 | return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size); | |
422 | } | |
423 | ||
424 | static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size) | |
425 | { | |
426 | if (name[0] != '\0') | |
427 | return -EINVAL; | |
428 | return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size); | |
429 | } | |
430 | ||
431 | static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size) | |
432 | { | |
433 | struct posix_acl *acl; | |
434 | int rc; | |
435 | ||
436 | if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) | |
437 | return -EPERM; | |
438 | ||
439 | if (value) { | |
440 | acl = posix_acl_from_xattr(value, size); | |
441 | if (IS_ERR(acl)) | |
442 | return PTR_ERR(acl); | |
443 | if (acl) { | |
444 | rc = posix_acl_valid(acl); | |
445 | if (rc) | |
446 | goto out; | |
447 | } | |
448 | } else { | |
449 | acl = NULL; | |
450 | } | |
451 | rc = jffs2_set_acl(inode, type, acl); | |
452 | out: | |
453 | posix_acl_release(acl); | |
454 | return rc; | |
455 | } | |
456 | ||
457 | static int jffs2_acl_access_setxattr(struct inode *inode, const char *name, | |
458 | const void *buffer, size_t size, int flags) | |
459 | { | |
460 | if (name[0] != '\0') | |
461 | return -EINVAL; | |
462 | return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size); | |
463 | } | |
464 | ||
465 | static int jffs2_acl_default_setxattr(struct inode *inode, const char *name, | |
466 | const void *buffer, size_t size, int flags) | |
467 | { | |
468 | if (name[0] != '\0') | |
469 | return -EINVAL; | |
470 | return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size); | |
471 | } | |
472 | ||
473 | struct xattr_handler jffs2_acl_access_xattr_handler = { | |
474 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
475 | .list = jffs2_acl_access_listxattr, | |
476 | .get = jffs2_acl_access_getxattr, | |
477 | .set = jffs2_acl_access_setxattr, | |
478 | }; | |
479 | ||
480 | struct xattr_handler jffs2_acl_default_xattr_handler = { | |
481 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
482 | .list = jffs2_acl_default_listxattr, | |
483 | .get = jffs2_acl_default_getxattr, | |
484 | .set = jffs2_acl_default_setxattr, | |
485 | }; |