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12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/fs.h>
15#include <linux/sched.h>
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
24static size_t jffs2_acl_size(int count)
25{
26 if (count <= 4) {
27 return sizeof(struct jffs2_acl_header)
28 + count * sizeof(struct jffs2_acl_entry_short);
29 } else {
30 return sizeof(struct jffs2_acl_header)
31 + 4 * sizeof(struct jffs2_acl_entry_short)
32 + (count - 4) * sizeof(struct jffs2_acl_entry);
33 }
34}
35
36static int jffs2_acl_count(size_t size)
37{
38 size_t s;
39
40 size -= sizeof(struct jffs2_acl_header);
41 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
42 if (s < 0) {
43 if (size % sizeof(struct jffs2_acl_entry_short))
44 return -1;
45 return size / sizeof(struct jffs2_acl_entry_short);
46 } else {
47 if (s % sizeof(struct jffs2_acl_entry))
48 return -1;
49 return s / sizeof(struct jffs2_acl_entry) + 4;
50 }
51}
52
53static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
54{
55 void *end = value + size;
56 struct jffs2_acl_header *header = value;
57 struct jffs2_acl_entry *entry;
58 struct posix_acl *acl;
59 uint32_t ver;
60 int i, count;
61
62 if (!value)
63 return NULL;
64 if (size < sizeof(struct jffs2_acl_header))
65 return ERR_PTR(-EINVAL);
66 ver = je32_to_cpu(header->a_version);
67 if (ver != JFFS2_ACL_VERSION) {
68 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
69 return ERR_PTR(-EINVAL);
70 }
71
72 value += sizeof(struct jffs2_acl_header);
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++) {
84 entry = value;
85 if (value + sizeof(struct jffs2_acl_entry_short) > end)
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:
94 value += sizeof(struct jffs2_acl_entry_short);
95 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
96 break;
97
98 case ACL_USER:
99 case ACL_GROUP:
100 value += sizeof(struct jffs2_acl_entry);
101 if (value > end)
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
118static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
119{
120 struct jffs2_acl_header *header;
121 struct jffs2_acl_entry *entry;
122 void *e;
123 size_t i;
124
125 *size = jffs2_acl_size(acl->a_count);
126 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
127 if (!header)
128 return ERR_PTR(-ENOMEM);
129 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
130 e = header + 1;
131 for (i=0; i < acl->a_count; i++) {
132 entry = e;
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);
139 e += sizeof(struct jffs2_acl_entry);
140 break;
141
142 case ACL_USER_OBJ:
143 case ACL_GROUP_OBJ:
144 case ACL_MASK:
145 case ACL_OTHER:
146 e += sizeof(struct jffs2_acl_entry_short);
147 break;
148
149 default:
150 goto fail;
151 }
152 }
153 return header;
154 fail:
155 kfree(header);
156 return ERR_PTR(-EINVAL);
157}
158
159static 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
170static 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
179struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
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
231static 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
250static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
251{
252 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
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) {
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;
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 }
287 rc = __jffs2_set_acl(inode, xprefix, acl);
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
301static 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
317int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
318{
319 return generic_permission(inode, mask, jffs2_check_acl);
320}
321
322int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode)
323{
324 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
325 struct posix_acl *acl, *clone;
326 int rc;
327
328 f->i_acl_default = NULL;
329 f->i_acl_access = NULL;
330
331 if (S_ISLNK(*i_mode))
332 return 0;
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);
343
344 clone = posix_acl_clone(acl, GFP_KERNEL);
345 if (!clone)
346 return -ENOMEM;
347 rc = posix_acl_create_masq(clone, (mode_t *)i_mode);
348 if (rc < 0)
349 return rc;
350 if (rc > 0)
351 jffs2_iset_acl(inode, &f->i_acl_access, clone);
352
353 posix_acl_release(clone);
354 }
355 return 0;
356}
357
358int jffs2_init_acl_post(struct inode *inode)
359{
360 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
361 int rc;
362
363 if (f->i_acl_default) {
364 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, f->i_acl_default);
365 if (rc)
366 return rc;
367 }
368
369 if (f->i_acl_access) {
370 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, f->i_acl_access);
371 if (rc)
372 return rc;
373 }
374
375 return 0;
376}
377
378void jffs2_clear_acl(struct jffs2_inode_info *f)
379{
380 if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
381 posix_acl_release(f->i_acl_access);
382 f->i_acl_access = JFFS2_ACL_NOT_CACHED;
383 }
384 if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
385 posix_acl_release(f->i_acl_default);
386 f->i_acl_default = JFFS2_ACL_NOT_CACHED;
387 }
388}
389
390int jffs2_acl_chmod(struct inode *inode)
391{
392 struct posix_acl *acl, *clone;
393 int rc;
394
395 if (S_ISLNK(inode->i_mode))
396 return -EOPNOTSUPP;
397 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
398 if (IS_ERR(acl) || !acl)
399 return PTR_ERR(acl);
400 clone = posix_acl_clone(acl, GFP_KERNEL);
401 posix_acl_release(acl);
402 if (!clone)
403 return -ENOMEM;
404 rc = posix_acl_chmod_masq(clone, inode->i_mode);
405 if (!rc)
406 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
407 posix_acl_release(clone);
408 return rc;
409}
410
411static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
412 const char *name, size_t name_len)
413{
414 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
415
416 if (list && retlen <= list_size)
417 strcpy(list, POSIX_ACL_XATTR_ACCESS);
418 return retlen;
419}
420
421static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
422 const char *name, size_t name_len)
423{
424 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
425
426 if (list && retlen <= list_size)
427 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
428 return retlen;
429}
430
431static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
432{
433 struct posix_acl *acl;
434 int rc;
435
436 acl = jffs2_get_acl(inode, type);
437 if (IS_ERR(acl))
438 return PTR_ERR(acl);
439 if (!acl)
440 return -ENODATA;
441 rc = posix_acl_to_xattr(acl, buffer, size);
442 posix_acl_release(acl);
443
444 return rc;
445}
446
447static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
448{
449 if (name[0] != '\0')
450 return -EINVAL;
451 return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
452}
453
454static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
455{
456 if (name[0] != '\0')
457 return -EINVAL;
458 return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
459}
460
461static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
462{
463 struct posix_acl *acl;
464 int rc;
465
466 if (!is_owner_or_cap(inode))
467 return -EPERM;
468
469 if (value) {
470 acl = posix_acl_from_xattr(value, size);
471 if (IS_ERR(acl))
472 return PTR_ERR(acl);
473 if (acl) {
474 rc = posix_acl_valid(acl);
475 if (rc)
476 goto out;
477 }
478 } else {
479 acl = NULL;
480 }
481 rc = jffs2_set_acl(inode, type, acl);
482 out:
483 posix_acl_release(acl);
484 return rc;
485}
486
487static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
488 const void *buffer, size_t size, int flags)
489{
490 if (name[0] != '\0')
491 return -EINVAL;
492 return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
493}
494
495static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
496 const void *buffer, size_t size, int flags)
497{
498 if (name[0] != '\0')
499 return -EINVAL;
500 return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
501}
502
503struct xattr_handler jffs2_acl_access_xattr_handler = {
504 .prefix = POSIX_ACL_XATTR_ACCESS,
505 .list = jffs2_acl_access_listxattr,
506 .get = jffs2_acl_access_getxattr,
507 .set = jffs2_acl_access_setxattr,
508};
509
510struct xattr_handler jffs2_acl_default_xattr_handler = {
511 .prefix = POSIX_ACL_XATTR_DEFAULT,
512 .list = jffs2_acl_default_listxattr,
513 .get = jffs2_acl_default_getxattr,
514 .set = jffs2_acl_default_setxattr,
515};
516
