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7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/slab.h>
10#include <linux/capability.h>
11#include <linux/fs.h>
12#include <linux/ext3_jbd.h>
13#include <linux/ext3_fs.h>
14#include "xattr.h"
15#include "acl.h"
16
17
18
19
20static struct posix_acl *
21ext3_acl_from_disk(const void *value, size_t size)
22{
23 const char *end = (char *)value + size;
24 int n, count;
25 struct posix_acl *acl;
26
27 if (!value)
28 return NULL;
29 if (size < sizeof(ext3_acl_header))
30 return ERR_PTR(-EINVAL);
31 if (((ext3_acl_header *)value)->a_version !=
32 cpu_to_le32(EXT3_ACL_VERSION))
33 return ERR_PTR(-EINVAL);
34 value = (char *)value + sizeof(ext3_acl_header);
35 count = ext3_acl_count(size);
36 if (count < 0)
37 return ERR_PTR(-EINVAL);
38 if (count == 0)
39 return NULL;
40 acl = posix_acl_alloc(count, GFP_NOFS);
41 if (!acl)
42 return ERR_PTR(-ENOMEM);
43 for (n=0; n < count; n++) {
44 ext3_acl_entry *entry =
45 (ext3_acl_entry *)value;
46 if ((char *)value + sizeof(ext3_acl_entry_short) > end)
47 goto fail;
48 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
49 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
50 switch(acl->a_entries[n].e_tag) {
51 case ACL_USER_OBJ:
52 case ACL_GROUP_OBJ:
53 case ACL_MASK:
54 case ACL_OTHER:
55 value = (char *)value +
56 sizeof(ext3_acl_entry_short);
57 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
58 break;
59
60 case ACL_USER:
61 case ACL_GROUP:
62 value = (char *)value + sizeof(ext3_acl_entry);
63 if ((char *)value > end)
64 goto fail;
65 acl->a_entries[n].e_id =
66 le32_to_cpu(entry->e_id);
67 break;
68
69 default:
70 goto fail;
71 }
72 }
73 if (value != end)
74 goto fail;
75 return acl;
76
77fail:
78 posix_acl_release(acl);
79 return ERR_PTR(-EINVAL);
80}
81
82
83
84
85static void *
86ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
87{
88 ext3_acl_header *ext_acl;
89 char *e;
90 size_t n;
91
92 *size = ext3_acl_size(acl->a_count);
93 ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
94 sizeof(ext3_acl_entry), GFP_NOFS);
95 if (!ext_acl)
96 return ERR_PTR(-ENOMEM);
97 ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
98 e = (char *)ext_acl + sizeof(ext3_acl_header);
99 for (n=0; n < acl->a_count; n++) {
100 ext3_acl_entry *entry = (ext3_acl_entry *)e;
101 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
102 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
103 switch(acl->a_entries[n].e_tag) {
104 case ACL_USER:
105 case ACL_GROUP:
106 entry->e_id =
107 cpu_to_le32(acl->a_entries[n].e_id);
108 e += sizeof(ext3_acl_entry);
109 break;
110
111 case ACL_USER_OBJ:
112 case ACL_GROUP_OBJ:
113 case ACL_MASK:
114 case ACL_OTHER:
115 e += sizeof(ext3_acl_entry_short);
116 break;
117
118 default:
119 goto fail;
120 }
121 }
122 return (char *)ext_acl;
123
124fail:
125 kfree(ext_acl);
126 return ERR_PTR(-EINVAL);
127}
128
129
130
131
132
133
134static struct posix_acl *
135ext3_get_acl(struct inode *inode, int type)
136{
137 int name_index;
138 char *value = NULL;
139 struct posix_acl *acl;
140 int retval;
141
142 if (!test_opt(inode->i_sb, POSIX_ACL))
143 return NULL;
144
145 acl = get_cached_acl(inode, type);
146 if (acl != ACL_NOT_CACHED)
147 return acl;
148
149 switch (type) {
150 case ACL_TYPE_ACCESS:
151 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
152 break;
153 case ACL_TYPE_DEFAULT:
154 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
155 break;
156 default:
157 BUG();
158 }
159
160 retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
161 if (retval > 0) {
162 value = kmalloc(retval, GFP_NOFS);
163 if (!value)
164 return ERR_PTR(-ENOMEM);
165 retval = ext3_xattr_get(inode, name_index, "", value, retval);
166 }
167 if (retval > 0)
168 acl = ext3_acl_from_disk(value, retval);
169 else if (retval == -ENODATA || retval == -ENOSYS)
170 acl = NULL;
171 else
172 acl = ERR_PTR(retval);
173 kfree(value);
174
175 if (!IS_ERR(acl))
176 set_cached_acl(inode, type, acl);
177
178 return acl;
179}
180
181
182
183
184
185
186static int
187ext3_set_acl(handle_t *handle, struct inode *inode, int type,
188 struct posix_acl *acl)
189{
190 int name_index;
191 void *value = NULL;
192 size_t size = 0;
193 int error;
194
195 if (S_ISLNK(inode->i_mode))
196 return -EOPNOTSUPP;
197
198 switch(type) {
199 case ACL_TYPE_ACCESS:
200 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
201 if (acl) {
202 mode_t mode = inode->i_mode;
203 error = posix_acl_equiv_mode(acl, &mode);
204 if (error < 0)
205 return error;
206 else {
207 inode->i_mode = mode;
208 inode->i_ctime = CURRENT_TIME_SEC;
209 ext3_mark_inode_dirty(handle, inode);
210 if (error == 0)
211 acl = NULL;
212 }
213 }
214 break;
215
216 case ACL_TYPE_DEFAULT:
217 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
218 if (!S_ISDIR(inode->i_mode))
219 return acl ? -EACCES : 0;
220 break;
221
222 default:
223 return -EINVAL;
224 }
225 if (acl) {
226 value = ext3_acl_to_disk(acl, &size);
227 if (IS_ERR(value))
228 return (int)PTR_ERR(value);
229 }
230
231 error = ext3_xattr_set_handle(handle, inode, name_index, "",
232 value, size, 0);
233
234 kfree(value);
235
236 if (!error)
237 set_cached_acl(inode, type, acl);
238
239 return error;
240}
241
242int
243ext3_check_acl(struct inode *inode, int mask, unsigned int flags)
244{
245 struct posix_acl *acl;
246
247 if (flags & IPERM_FLAG_RCU) {
248 if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
249 return -ECHILD;
250 return -EAGAIN;
251 }
252
253 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
254 if (IS_ERR(acl))
255 return PTR_ERR(acl);
256 if (acl) {
257 int error = posix_acl_permission(inode, acl, mask);
258 posix_acl_release(acl);
259 return error;
260 }
261
262 return -EAGAIN;
263}
264
265
266
267
268
269
270
271int
272ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
273{
274 struct posix_acl *acl = NULL;
275 int error = 0;
276
277 if (!S_ISLNK(inode->i_mode)) {
278 if (test_opt(dir->i_sb, POSIX_ACL)) {
279 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
280 if (IS_ERR(acl))
281 return PTR_ERR(acl);
282 }
283 if (!acl)
284 inode->i_mode &= ~current_umask();
285 }
286 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
287 struct posix_acl *clone;
288 mode_t mode;
289
290 if (S_ISDIR(inode->i_mode)) {
291 error = ext3_set_acl(handle, inode,
292 ACL_TYPE_DEFAULT, acl);
293 if (error)
294 goto cleanup;
295 }
296 clone = posix_acl_clone(acl, GFP_NOFS);
297 error = -ENOMEM;
298 if (!clone)
299 goto cleanup;
300
301 mode = inode->i_mode;
302 error = posix_acl_create_masq(clone, &mode);
303 if (error >= 0) {
304 inode->i_mode = mode;
305 if (error > 0) {
306
307 error = ext3_set_acl(handle, inode,
308 ACL_TYPE_ACCESS, clone);
309 }
310 }
311 posix_acl_release(clone);
312 }
313cleanup:
314 posix_acl_release(acl);
315 return error;
316}
317
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319
320
321
322
323
324
325
326
327
328
329
330
331
332int
333ext3_acl_chmod(struct inode *inode)
334{
335 struct posix_acl *acl, *clone;
336 int error;
337
338 if (S_ISLNK(inode->i_mode))
339 return -EOPNOTSUPP;
340 if (!test_opt(inode->i_sb, POSIX_ACL))
341 return 0;
342 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
343 if (IS_ERR(acl) || !acl)
344 return PTR_ERR(acl);
345 clone = posix_acl_clone(acl, GFP_KERNEL);
346 posix_acl_release(acl);
347 if (!clone)
348 return -ENOMEM;
349 error = posix_acl_chmod_masq(clone, inode->i_mode);
350 if (!error) {
351 handle_t *handle;
352 int retries = 0;
353
354 retry:
355 handle = ext3_journal_start(inode,
356 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
357 if (IS_ERR(handle)) {
358 error = PTR_ERR(handle);
359 ext3_std_error(inode->i_sb, error);
360 goto out;
361 }
362 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
363 ext3_journal_stop(handle);
364 if (error == -ENOSPC &&
365 ext3_should_retry_alloc(inode->i_sb, &retries))
366 goto retry;
367 }
368out:
369 posix_acl_release(clone);
370 return error;
371}
372
373
374
375
376static size_t
377ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
378 const char *name, size_t name_len, int type)
379{
380 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
381
382 if (!test_opt(dentry->d_sb, POSIX_ACL))
383 return 0;
384 if (list && size <= list_len)
385 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
386 return size;
387}
388
389static size_t
390ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
391 const char *name, size_t name_len, int type)
392{
393 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
394
395 if (!test_opt(dentry->d_sb, POSIX_ACL))
396 return 0;
397 if (list && size <= list_len)
398 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
399 return size;
400}
401
402static int
403ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
404 size_t size, int type)
405{
406 struct posix_acl *acl;
407 int error;
408
409 if (strcmp(name, "") != 0)
410 return -EINVAL;
411 if (!test_opt(dentry->d_sb, POSIX_ACL))
412 return -EOPNOTSUPP;
413
414 acl = ext3_get_acl(dentry->d_inode, type);
415 if (IS_ERR(acl))
416 return PTR_ERR(acl);
417 if (acl == NULL)
418 return -ENODATA;
419 error = posix_acl_to_xattr(acl, buffer, size);
420 posix_acl_release(acl);
421
422 return error;
423}
424
425static int
426ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
427 size_t size, int flags, int type)
428{
429 struct inode *inode = dentry->d_inode;
430 handle_t *handle;
431 struct posix_acl *acl;
432 int error, retries = 0;
433
434 if (strcmp(name, "") != 0)
435 return -EINVAL;
436 if (!test_opt(inode->i_sb, POSIX_ACL))
437 return -EOPNOTSUPP;
438 if (!is_owner_or_cap(inode))
439 return -EPERM;
440
441 if (value) {
442 acl = posix_acl_from_xattr(value, size);
443 if (IS_ERR(acl))
444 return PTR_ERR(acl);
445 else if (acl) {
446 error = posix_acl_valid(acl);
447 if (error)
448 goto release_and_out;
449 }
450 } else
451 acl = NULL;
452
453retry:
454 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
455 if (IS_ERR(handle))
456 return PTR_ERR(handle);
457 error = ext3_set_acl(handle, inode, type, acl);
458 ext3_journal_stop(handle);
459 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
460 goto retry;
461
462release_and_out:
463 posix_acl_release(acl);
464 return error;
465}
466
467const struct xattr_handler ext3_xattr_acl_access_handler = {
468 .prefix = POSIX_ACL_XATTR_ACCESS,
469 .flags = ACL_TYPE_ACCESS,
470 .list = ext3_xattr_list_acl_access,
471 .get = ext3_xattr_get_acl,
472 .set = ext3_xattr_set_acl,
473};
474
475const struct xattr_handler ext3_xattr_acl_default_handler = {
476 .prefix = POSIX_ACL_XATTR_DEFAULT,
477 .flags = ACL_TYPE_DEFAULT,
478 .list = ext3_xattr_list_acl_default,
479 .get = ext3_xattr_get_acl,
480 .set = ext3_xattr_set_acl,
481};
482
