1 /*-------------------------------------------------------------------------*
3 * POSIX ACL support on JFFS2 FileSystem
5 * Implemented by KaiGai Kohei <kaigai@ak.jp.nec.com>
6 * Copyright (C) 2006 NEC Corporation
8 * For licensing information, see the file 'LICENCE' in the jffs2 directory.
9 *-------------------------------------------------------------------------*/
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
13 #include <linux/time.h>
14 #include <linux/crc32.h>
15 #include <linux/jffs2.h>
16 #include <linux/xattr.h>
17 #include <linux/posix_acl_xattr.h>
18 #include <linux/mtd/mtd.h>
21 static size_t jffs2_acl_size(int count)
24 return sizeof(struct jffs2_acl_header)
25 + count * sizeof(struct jffs2_acl_entry_short);
27 return sizeof(struct jffs2_acl_header)
28 + 4 * sizeof(struct jffs2_acl_entry_short)
29 + (count - 4) * sizeof(struct jffs2_acl_entry);
33 static int jffs2_acl_count(size_t size)
37 size -= sizeof(struct jffs2_acl_header);
38 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
40 if (size % sizeof(struct jffs2_acl_entry_short))
42 return size / sizeof(struct jffs2_acl_entry_short);
44 if (s % sizeof(struct jffs2_acl_entry))
46 return s / sizeof(struct jffs2_acl_entry) + 4;
50 static struct posix_acl *jffs2_acl_from_medium(const void *value, size_t size)
52 const char *end = (char *)value + size;
53 struct posix_acl *acl;
59 if (size < sizeof(struct jffs2_acl_header))
60 return ERR_PTR(-EINVAL);
61 ver = je32_to_cpu(((struct jffs2_acl_header *)value)->a_version);
62 if (ver != JFFS2_ACL_VERSION) {
63 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
64 return ERR_PTR(-EINVAL);
67 value = (char *)value + sizeof(struct jffs2_acl_header);
68 count = jffs2_acl_count(size);
70 return ERR_PTR(-EINVAL);
74 acl = posix_acl_alloc(count, GFP_KERNEL);
76 return ERR_PTR(-ENOMEM);
78 for (i=0; i < count; i++) {
79 struct jffs2_acl_entry *entry = (struct jffs2_acl_entry *)value;
80 if ((char *)value + sizeof(struct jffs2_acl_entry_short) > end)
82 acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
83 acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
84 switch (acl->a_entries[i].e_tag) {
89 value = (char *)value + sizeof(struct jffs2_acl_entry_short);
90 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
95 value = (char *)value + sizeof(struct jffs2_acl_entry);
96 if ((char *)value > end)
98 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
109 posix_acl_release(acl);
110 return ERR_PTR(-EINVAL);
113 static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
115 struct jffs2_acl_header *jffs2_acl;
119 *size = jffs2_acl_size(acl->a_count);
120 jffs2_acl = kmalloc(sizeof(struct jffs2_acl_header)
121 + acl->a_count * sizeof(struct jffs2_acl_entry),
124 return ERR_PTR(-ENOMEM);
125 jffs2_acl->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
126 e = (char *)jffs2_acl + sizeof(struct jffs2_acl_header);
127 for (i=0; i < acl->a_count; i++) {
128 struct jffs2_acl_entry *entry = (struct jffs2_acl_entry *)e;
129 entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
130 entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
131 switch(acl->a_entries[i].e_tag) {
134 entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
135 e += sizeof(struct jffs2_acl_entry);
142 e += sizeof(struct jffs2_acl_entry_short);
149 return (char *)jffs2_acl;
152 return ERR_PTR(-EINVAL);
155 static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
157 struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;
159 spin_lock(&inode->i_lock);
160 if (*i_acl != JFFS2_ACL_NOT_CACHED)
161 acl = posix_acl_dup(*i_acl);
162 spin_unlock(&inode->i_lock);
166 static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
168 spin_lock(&inode->i_lock);
169 if (*i_acl != JFFS2_ACL_NOT_CACHED)
170 posix_acl_release(*i_acl);
171 *i_acl = posix_acl_dup(acl);
172 spin_unlock(&inode->i_lock);
175 static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
177 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
178 struct posix_acl *acl;
183 case ACL_TYPE_ACCESS:
184 acl = jffs2_iget_acl(inode, &f->i_acl_access);
185 if (acl != JFFS2_ACL_NOT_CACHED)
187 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
189 case ACL_TYPE_DEFAULT:
190 acl = jffs2_iget_acl(inode, &f->i_acl_default);
191 if (acl != JFFS2_ACL_NOT_CACHED)
193 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
196 return ERR_PTR(-EINVAL);
198 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
200 value = kmalloc(rc, GFP_KERNEL);
202 return ERR_PTR(-ENOMEM);
203 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
206 acl = jffs2_acl_from_medium(value, rc);
207 } else if (rc == -ENODATA || rc == -ENOSYS) {
216 case ACL_TYPE_ACCESS:
217 jffs2_iset_acl(inode, &f->i_acl_access, acl);
219 case ACL_TYPE_DEFAULT:
220 jffs2_iset_acl(inode, &f->i_acl_default, acl);
227 static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
229 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
234 if (S_ISLNK(inode->i_mode))
238 case ACL_TYPE_ACCESS:
239 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
241 mode_t mode = inode->i_mode;
242 rc = posix_acl_equiv_mode(acl, &mode);
245 if (inode->i_mode != mode) {
246 inode->i_mode = mode;
247 jffs2_dirty_inode(inode);
253 case ACL_TYPE_DEFAULT:
254 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
255 if (!S_ISDIR(inode->i_mode))
256 return acl ? -EACCES : 0;
262 value = jffs2_acl_to_medium(acl, &size);
264 return PTR_ERR(value);
267 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
272 case ACL_TYPE_ACCESS:
273 jffs2_iset_acl(inode, &f->i_acl_access, acl);
275 case ACL_TYPE_DEFAULT:
276 jffs2_iset_acl(inode, &f->i_acl_default, acl);
283 static int jffs2_check_acl(struct inode *inode, int mask)
285 struct posix_acl *acl;
288 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
292 rc = posix_acl_permission(inode, acl, mask);
293 posix_acl_release(acl);
299 int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
301 return generic_permission(inode, mask, jffs2_check_acl);
304 int jffs2_init_acl(struct inode *inode, struct inode *dir)
306 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
307 struct posix_acl *acl = NULL, *clone;
311 f->i_acl_access = JFFS2_ACL_NOT_CACHED;
312 f->i_acl_default = JFFS2_ACL_NOT_CACHED;
313 if (!S_ISLNK(inode->i_mode)) {
314 acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
318 inode->i_mode &= ~current->fs->umask;
321 if (S_ISDIR(inode->i_mode)) {
322 rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
326 clone = posix_acl_clone(acl, GFP_KERNEL);
330 mode = inode->i_mode;
331 rc = posix_acl_create_masq(clone, &mode);
333 inode->i_mode = mode;
335 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
337 posix_acl_release(clone);
340 posix_acl_release(acl);
344 void jffs2_clear_acl(struct inode *inode)
346 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
348 if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
349 posix_acl_release(f->i_acl_access);
350 f->i_acl_access = JFFS2_ACL_NOT_CACHED;
352 if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
353 posix_acl_release(f->i_acl_default);
354 f->i_acl_default = JFFS2_ACL_NOT_CACHED;
358 int jffs2_acl_chmod(struct inode *inode)
360 struct posix_acl *acl, *clone;
363 if (S_ISLNK(inode->i_mode))
365 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
366 if (IS_ERR(acl) || !acl)
368 clone = posix_acl_clone(acl, GFP_KERNEL);
369 posix_acl_release(acl);
372 rc = posix_acl_chmod_masq(clone, inode->i_mode);
374 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
375 posix_acl_release(clone);
379 static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
380 const char *name, size_t name_len)
382 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
384 if (list && retlen <= list_size)
385 strcpy(list, POSIX_ACL_XATTR_ACCESS);
389 static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
390 const char *name, size_t name_len)
392 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
394 if (list && retlen <= list_size)
395 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
399 static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
401 struct posix_acl *acl;
404 acl = jffs2_get_acl(inode, type);
409 rc = posix_acl_to_xattr(acl, buffer, size);
410 posix_acl_release(acl);
415 static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
419 return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
422 static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
426 return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
429 static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
431 struct posix_acl *acl;
434 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
438 acl = posix_acl_from_xattr(value, size);
442 rc = posix_acl_valid(acl);
449 rc = jffs2_set_acl(inode, type, acl);
451 posix_acl_release(acl);
455 static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
456 const void *buffer, size_t size, int flags)
460 return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
463 static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
464 const void *buffer, size_t size, int flags)
468 return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
471 struct xattr_handler jffs2_acl_access_xattr_handler = {
472 .prefix = POSIX_ACL_XATTR_ACCESS,
473 .list = jffs2_acl_access_listxattr,
474 .get = jffs2_acl_access_getxattr,
475 .set = jffs2_acl_access_setxattr,
478 struct xattr_handler jffs2_acl_default_xattr_handler = {
479 .prefix = POSIX_ACL_XATTR_DEFAULT,
480 .list = jffs2_acl_default_listxattr,
481 .get = jffs2_acl_default_getxattr,
482 .set = jffs2_acl_default_setxattr,