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7#include <linux/capability.h>
8#include <linux/init.h>
9#include <linux/sched.h>
10#include <linux/slab.h>
11#include <linux/fs.h>
12#include "ext2.h"
13#include "xattr.h"
14#include "acl.h"
15
16
17
18
19static struct posix_acl *
20ext2_acl_from_disk(const void *value, size_t size)
21{
22 const char *end = (char *)value + size;
23 int n, count;
24 struct posix_acl *acl;
25
26 if (!value)
27 return NULL;
28 if (size < sizeof(ext2_acl_header))
29 return ERR_PTR(-EINVAL);
30 if (((ext2_acl_header *)value)->a_version !=
31 cpu_to_le32(EXT2_ACL_VERSION))
32 return ERR_PTR(-EINVAL);
33 value = (char *)value + sizeof(ext2_acl_header);
34 count = ext2_acl_count(size);
35 if (count < 0)
36 return ERR_PTR(-EINVAL);
37 if (count == 0)
38 return NULL;
39 acl = posix_acl_alloc(count, GFP_KERNEL);
40 if (!acl)
41 return ERR_PTR(-ENOMEM);
42 for (n=0; n < count; n++) {
43 ext2_acl_entry *entry =
44 (ext2_acl_entry *)value;
45 if ((char *)value + sizeof(ext2_acl_entry_short) > end)
46 goto fail;
47 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
48 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
49 switch(acl->a_entries[n].e_tag) {
50 case ACL_USER_OBJ:
51 case ACL_GROUP_OBJ:
52 case ACL_MASK:
53 case ACL_OTHER:
54 value = (char *)value +
55 sizeof(ext2_acl_entry_short);
56 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
57 break;
58
59 case ACL_USER:
60 case ACL_GROUP:
61 value = (char *)value + sizeof(ext2_acl_entry);
62 if ((char *)value > end)
63 goto fail;
64 acl->a_entries[n].e_id =
65 le32_to_cpu(entry->e_id);
66 break;
67
68 default:
69 goto fail;
70 }
71 }
72 if (value != end)
73 goto fail;
74 return acl;
75
76fail:
77 posix_acl_release(acl);
78 return ERR_PTR(-EINVAL);
79}
80
81
82
83
84static void *
85ext2_acl_to_disk(const struct posix_acl *acl, size_t *size)
86{
87 ext2_acl_header *ext_acl;
88 char *e;
89 size_t n;
90
91 *size = ext2_acl_size(acl->a_count);
92 ext_acl = kmalloc(sizeof(ext2_acl_header) + acl->a_count *
93 sizeof(ext2_acl_entry), GFP_KERNEL);
94 if (!ext_acl)
95 return ERR_PTR(-ENOMEM);
96 ext_acl->a_version = cpu_to_le32(EXT2_ACL_VERSION);
97 e = (char *)ext_acl + sizeof(ext2_acl_header);
98 for (n=0; n < acl->a_count; n++) {
99 ext2_acl_entry *entry = (ext2_acl_entry *)e;
100 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
101 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
102 switch(acl->a_entries[n].e_tag) {
103 case ACL_USER:
104 case ACL_GROUP:
105 entry->e_id =
106 cpu_to_le32(acl->a_entries[n].e_id);
107 e += sizeof(ext2_acl_entry);
108 break;
109
110 case ACL_USER_OBJ:
111 case ACL_GROUP_OBJ:
112 case ACL_MASK:
113 case ACL_OTHER:
114 e += sizeof(ext2_acl_entry_short);
115 break;
116
117 default:
118 goto fail;
119 }
120 }
121 return (char *)ext_acl;
122
123fail:
124 kfree(ext_acl);
125 return ERR_PTR(-EINVAL);
126}
127
128
129
130
131static struct posix_acl *
132ext2_get_acl(struct inode *inode, int type)
133{
134 int name_index;
135 char *value = NULL;
136 struct posix_acl *acl;
137 int retval;
138
139 if (!test_opt(inode->i_sb, POSIX_ACL))
140 return NULL;
141
142 acl = get_cached_acl(inode, type);
143 if (acl != ACL_NOT_CACHED)
144 return acl;
145
146 switch (type) {
147 case ACL_TYPE_ACCESS:
148 name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
149 break;
150 case ACL_TYPE_DEFAULT:
151 name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
152 break;
153 default:
154 BUG();
155 }
156 retval = ext2_xattr_get(inode, name_index, "", NULL, 0);
157 if (retval > 0) {
158 value = kmalloc(retval, GFP_KERNEL);
159 if (!value)
160 return ERR_PTR(-ENOMEM);
161 retval = ext2_xattr_get(inode, name_index, "", value, retval);
162 }
163 if (retval > 0)
164 acl = ext2_acl_from_disk(value, retval);
165 else if (retval == -ENODATA || retval == -ENOSYS)
166 acl = NULL;
167 else
168 acl = ERR_PTR(retval);
169 kfree(value);
170
171 if (!IS_ERR(acl))
172 set_cached_acl(inode, type, acl);
173
174 return acl;
175}
176
177
178
179
180static int
181ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
182{
183 int name_index;
184 void *value = NULL;
185 size_t size = 0;
186 int error;
187
188 if (S_ISLNK(inode->i_mode))
189 return -EOPNOTSUPP;
190 if (!test_opt(inode->i_sb, POSIX_ACL))
191 return 0;
192
193 switch(type) {
194 case ACL_TYPE_ACCESS:
195 name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
196 if (acl) {
197 mode_t mode = inode->i_mode;
198 error = posix_acl_equiv_mode(acl, &mode);
199 if (error < 0)
200 return error;
201 else {
202 inode->i_mode = mode;
203 mark_inode_dirty(inode);
204 if (error == 0)
205 acl = NULL;
206 }
207 }
208 break;
209
210 case ACL_TYPE_DEFAULT:
211 name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
212 if (!S_ISDIR(inode->i_mode))
213 return acl ? -EACCES : 0;
214 break;
215
216 default:
217 return -EINVAL;
218 }
219 if (acl) {
220 value = ext2_acl_to_disk(acl, &size);
221 if (IS_ERR(value))
222 return (int)PTR_ERR(value);
223 }
224
225 error = ext2_xattr_set(inode, name_index, "", value, size, 0);
226
227 kfree(value);
228 if (!error)
229 set_cached_acl(inode, type, acl);
230 return error;
231}
232
233int
234ext2_check_acl(struct inode *inode, int mask)
235{
236 struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
237
238 if (IS_ERR(acl))
239 return PTR_ERR(acl);
240 if (acl) {
241 int error = posix_acl_permission(inode, acl, mask);
242 posix_acl_release(acl);
243 return error;
244 }
245
246 return -EAGAIN;
247}
248
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252
253
254
255int
256ext2_init_acl(struct inode *inode, struct inode *dir)
257{
258 struct posix_acl *acl = NULL;
259 int error = 0;
260
261 if (!S_ISLNK(inode->i_mode)) {
262 if (test_opt(dir->i_sb, POSIX_ACL)) {
263 acl = ext2_get_acl(dir, ACL_TYPE_DEFAULT);
264 if (IS_ERR(acl))
265 return PTR_ERR(acl);
266 }
267 if (!acl)
268 inode->i_mode &= ~current_umask();
269 }
270 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
271 struct posix_acl *clone;
272 mode_t mode;
273
274 if (S_ISDIR(inode->i_mode)) {
275 error = ext2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
276 if (error)
277 goto cleanup;
278 }
279 clone = posix_acl_clone(acl, GFP_KERNEL);
280 error = -ENOMEM;
281 if (!clone)
282 goto cleanup;
283 mode = inode->i_mode;
284 error = posix_acl_create_masq(clone, &mode);
285 if (error >= 0) {
286 inode->i_mode = mode;
287 if (error > 0) {
288
289 error = ext2_set_acl(inode,
290 ACL_TYPE_ACCESS, clone);
291 }
292 }
293 posix_acl_release(clone);
294 }
295cleanup:
296 posix_acl_release(acl);
297 return error;
298}
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312
313
314int
315ext2_acl_chmod(struct inode *inode)
316{
317 struct posix_acl *acl, *clone;
318 int error;
319
320 if (!test_opt(inode->i_sb, POSIX_ACL))
321 return 0;
322 if (S_ISLNK(inode->i_mode))
323 return -EOPNOTSUPP;
324 acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
325 if (IS_ERR(acl) || !acl)
326 return PTR_ERR(acl);
327 clone = posix_acl_clone(acl, GFP_KERNEL);
328 posix_acl_release(acl);
329 if (!clone)
330 return -ENOMEM;
331 error = posix_acl_chmod_masq(clone, inode->i_mode);
332 if (!error)
333 error = ext2_set_acl(inode, ACL_TYPE_ACCESS, clone);
334 posix_acl_release(clone);
335 return error;
336}
337
338
339
340
341static size_t
342ext2_xattr_list_acl_access(struct inode *inode, char *list, size_t list_size,
343 const char *name, size_t name_len)
344{
345 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
346
347 if (!test_opt(inode->i_sb, POSIX_ACL))
348 return 0;
349 if (list && size <= list_size)
350 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
351 return size;
352}
353
354static size_t
355ext2_xattr_list_acl_default(struct inode *inode, char *list, size_t list_size,
356 const char *name, size_t name_len)
357{
358 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
359
360 if (!test_opt(inode->i_sb, POSIX_ACL))
361 return 0;
362 if (list && size <= list_size)
363 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
364 return size;
365}
366
367static int
368ext2_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
369{
370 struct posix_acl *acl;
371 int error;
372
373 if (!test_opt(inode->i_sb, POSIX_ACL))
374 return -EOPNOTSUPP;
375
376 acl = ext2_get_acl(inode, type);
377 if (IS_ERR(acl))
378 return PTR_ERR(acl);
379 if (acl == NULL)
380 return -ENODATA;
381 error = posix_acl_to_xattr(acl, buffer, size);
382 posix_acl_release(acl);
383
384 return error;
385}
386
387static int
388ext2_xattr_get_acl_access(struct inode *inode, const char *name,
389 void *buffer, size_t size)
390{
391 if (strcmp(name, "") != 0)
392 return -EINVAL;
393 return ext2_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
394}
395
396static int
397ext2_xattr_get_acl_default(struct inode *inode, const char *name,
398 void *buffer, size_t size)
399{
400 if (strcmp(name, "") != 0)
401 return -EINVAL;
402 return ext2_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
403}
404
405static int
406ext2_xattr_set_acl(struct inode *inode, int type, const void *value,
407 size_t size)
408{
409 struct posix_acl *acl;
410 int error;
411
412 if (!test_opt(inode->i_sb, POSIX_ACL))
413 return -EOPNOTSUPP;
414 if (!is_owner_or_cap(inode))
415 return -EPERM;
416
417 if (value) {
418 acl = posix_acl_from_xattr(value, size);
419 if (IS_ERR(acl))
420 return PTR_ERR(acl);
421 else if (acl) {
422 error = posix_acl_valid(acl);
423 if (error)
424 goto release_and_out;
425 }
426 } else
427 acl = NULL;
428
429 error = ext2_set_acl(inode, type, acl);
430
431release_and_out:
432 posix_acl_release(acl);
433 return error;
434}
435
436static int
437ext2_xattr_set_acl_access(struct inode *inode, const char *name,
438 const void *value, size_t size, int flags)
439{
440 if (strcmp(name, "") != 0)
441 return -EINVAL;
442 return ext2_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
443}
444
445static int
446ext2_xattr_set_acl_default(struct inode *inode, const char *name,
447 const void *value, size_t size, int flags)
448{
449 if (strcmp(name, "") != 0)
450 return -EINVAL;
451 return ext2_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
452}
453
454struct xattr_handler ext2_xattr_acl_access_handler = {
455 .prefix = POSIX_ACL_XATTR_ACCESS,
456 .list = ext2_xattr_list_acl_access,
457 .get = ext2_xattr_get_acl_access,
458 .set = ext2_xattr_set_acl_access,
459};
460
461struct xattr_handler ext2_xattr_acl_default_handler = {
462 .prefix = POSIX_ACL_XATTR_DEFAULT,
463 .list = ext2_xattr_list_acl_default,
464 .get = ext2_xattr_get_acl_default,
465 .set = ext2_xattr_set_acl_default,
466};
467
