ia64/linux-2.6.18-xen.hg

view fs/jffs2/acl.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2006 NEC Corporation
5 *
6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
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"
22 static size_t jffs2_acl_size(int count)
23 {
24 if (count <= 4) {
25 return sizeof(struct jffs2_acl_header)
26 + count * sizeof(struct jffs2_acl_entry_short);
27 } else {
28 return sizeof(struct jffs2_acl_header)
29 + 4 * sizeof(struct jffs2_acl_entry_short)
30 + (count - 4) * sizeof(struct jffs2_acl_entry);
31 }
32 }
34 static int jffs2_acl_count(size_t size)
35 {
36 size_t s;
38 size -= sizeof(struct jffs2_acl_header);
39 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
40 if (s < 0) {
41 if (size % sizeof(struct jffs2_acl_entry_short))
42 return -1;
43 return size / sizeof(struct jffs2_acl_entry_short);
44 } else {
45 if (s % sizeof(struct jffs2_acl_entry))
46 return -1;
47 return s / sizeof(struct jffs2_acl_entry) + 4;
48 }
49 }
51 static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
52 {
53 void *end = value + size;
54 struct jffs2_acl_header *header = value;
55 struct jffs2_acl_entry *entry;
56 struct posix_acl *acl;
57 uint32_t ver;
58 int i, count;
60 if (!value)
61 return NULL;
62 if (size < sizeof(struct jffs2_acl_header))
63 return ERR_PTR(-EINVAL);
64 ver = je32_to_cpu(header->a_version);
65 if (ver != JFFS2_ACL_VERSION) {
66 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
67 return ERR_PTR(-EINVAL);
68 }
70 value += sizeof(struct jffs2_acl_header);
71 count = jffs2_acl_count(size);
72 if (count < 0)
73 return ERR_PTR(-EINVAL);
74 if (count == 0)
75 return NULL;
77 acl = posix_acl_alloc(count, GFP_KERNEL);
78 if (!acl)
79 return ERR_PTR(-ENOMEM);
81 for (i=0; i < count; i++) {
82 entry = value;
83 if (value + sizeof(struct jffs2_acl_entry_short) > end)
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:
92 value += sizeof(struct jffs2_acl_entry_short);
93 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
94 break;
96 case ACL_USER:
97 case ACL_GROUP:
98 value += sizeof(struct jffs2_acl_entry);
99 if (value > end)
100 goto fail;
101 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
102 break;
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 }
116 static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
117 {
118 struct jffs2_acl_header *header;
119 struct jffs2_acl_entry *entry;
120 void *e;
121 size_t i;
123 *size = jffs2_acl_size(acl->a_count);
124 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
125 if (!header)
126 return ERR_PTR(-ENOMEM);
127 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
128 e = header + 1;
129 for (i=0; i < acl->a_count; i++) {
130 entry = e;
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);
137 e += sizeof(struct jffs2_acl_entry);
138 break;
140 case ACL_USER_OBJ:
141 case ACL_GROUP_OBJ:
142 case ACL_MASK:
143 case ACL_OTHER:
144 e += sizeof(struct jffs2_acl_entry_short);
145 break;
147 default:
148 goto fail;
149 }
150 }
151 return header;
152 fail:
153 kfree(header);
154 return ERR_PTR(-EINVAL);
155 }
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;
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 }
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 }
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;
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 }
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;
236 if (S_ISLNK(inode->i_mode))
237 return -EOPNOTSUPP;
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 }
269 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
270 if (!value && rc == -ENODATA)
271 rc = 0;
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 }
287 static int jffs2_check_acl(struct inode *inode, int mask)
288 {
289 struct posix_acl *acl;
290 int rc;
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 }
303 int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
304 {
305 return generic_permission(inode, mask, jffs2_check_acl);
306 }
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;
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 }
348 void jffs2_clear_acl(struct jffs2_inode_info *f)
349 {
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 }
360 int jffs2_acl_chmod(struct inode *inode)
361 {
362 struct posix_acl *acl, *clone;
363 int rc;
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 }
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);
386 if (list && retlen <= list_size)
387 strcpy(list, POSIX_ACL_XATTR_ACCESS);
388 return retlen;
389 }
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);
396 if (list && retlen <= list_size)
397 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
398 return retlen;
399 }
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;
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);
414 return rc;
415 }
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 }
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 }
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;
436 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
437 return -EPERM;
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 }
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 }
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 }
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 };
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 };