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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 break;
57
58 case ACL_USER:
59 value = (char *)value + sizeof(ext2_acl_entry);
60 if ((char *)value > end)
61 goto fail;
62 acl->a_entries[n].e_uid =
63 make_kuid(&init_user_ns,
64 le32_to_cpu(entry->e_id));
65 break;
66 case ACL_GROUP:
67 value = (char *)value + sizeof(ext2_acl_entry);
68 if ((char *)value > end)
69 goto fail;
70 acl->a_entries[n].e_gid =
71 make_kgid(&init_user_ns,
72 le32_to_cpu(entry->e_id));
73 break;
74
75 default:
76 goto fail;
77 }
78 }
79 if (value != end)
80 goto fail;
81 return acl;
82
83fail:
84 posix_acl_release(acl);
85 return ERR_PTR(-EINVAL);
86}
87
88
89
90
91static void *
92ext2_acl_to_disk(const struct posix_acl *acl, size_t *size)
93{
94 ext2_acl_header *ext_acl;
95 char *e;
96 size_t n;
97
98 *size = ext2_acl_size(acl->a_count);
99 ext_acl = kmalloc(sizeof(ext2_acl_header) + acl->a_count *
100 sizeof(ext2_acl_entry), GFP_KERNEL);
101 if (!ext_acl)
102 return ERR_PTR(-ENOMEM);
103 ext_acl->a_version = cpu_to_le32(EXT2_ACL_VERSION);
104 e = (char *)ext_acl + sizeof(ext2_acl_header);
105 for (n=0; n < acl->a_count; n++) {
106 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
107 ext2_acl_entry *entry = (ext2_acl_entry *)e;
108 entry->e_tag = cpu_to_le16(acl_e->e_tag);
109 entry->e_perm = cpu_to_le16(acl_e->e_perm);
110 switch(acl_e->e_tag) {
111 case ACL_USER:
112 entry->e_id = cpu_to_le32(
113 from_kuid(&init_user_ns, acl_e->e_uid));
114 e += sizeof(ext2_acl_entry);
115 break;
116 case ACL_GROUP:
117 entry->e_id = cpu_to_le32(
118 from_kgid(&init_user_ns, acl_e->e_gid));
119 e += sizeof(ext2_acl_entry);
120 break;
121
122 case ACL_USER_OBJ:
123 case ACL_GROUP_OBJ:
124 case ACL_MASK:
125 case ACL_OTHER:
126 e += sizeof(ext2_acl_entry_short);
127 break;
128
129 default:
130 goto fail;
131 }
132 }
133 return (char *)ext_acl;
134
135fail:
136 kfree(ext_acl);
137 return ERR_PTR(-EINVAL);
138}
139
140
141
142
143struct posix_acl *
144ext2_get_acl(struct inode *inode, int type)
145{
146 int name_index;
147 char *value = NULL;
148 struct posix_acl *acl;
149 int retval;
150
151 if (!test_opt(inode->i_sb, POSIX_ACL))
152 return NULL;
153
154 acl = get_cached_acl(inode, type);
155 if (acl != ACL_NOT_CACHED)
156 return acl;
157
158 switch (type) {
159 case ACL_TYPE_ACCESS:
160 name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
161 break;
162 case ACL_TYPE_DEFAULT:
163 name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
164 break;
165 default:
166 BUG();
167 }
168 retval = ext2_xattr_get(inode, name_index, "", NULL, 0);
169 if (retval > 0) {
170 value = kmalloc(retval, GFP_KERNEL);
171 if (!value)
172 return ERR_PTR(-ENOMEM);
173 retval = ext2_xattr_get(inode, name_index, "", value, retval);
174 }
175 if (retval > 0)
176 acl = ext2_acl_from_disk(value, retval);
177 else if (retval == -ENODATA || retval == -ENOSYS)
178 acl = NULL;
179 else
180 acl = ERR_PTR(retval);
181 kfree(value);
182
183 if (!IS_ERR(acl))
184 set_cached_acl(inode, type, acl);
185
186 return acl;
187}
188
189
190
191
192static int
193ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
194{
195 int name_index;
196 void *value = NULL;
197 size_t size = 0;
198 int error;
199
200 if (S_ISLNK(inode->i_mode))
201 return -EOPNOTSUPP;
202 if (!test_opt(inode->i_sb, POSIX_ACL))
203 return 0;
204
205 switch(type) {
206 case ACL_TYPE_ACCESS:
207 name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
208 if (acl) {
209 error = posix_acl_equiv_mode(acl, &inode->i_mode);
210 if (error < 0)
211 return error;
212 else {
213 inode->i_ctime = CURRENT_TIME_SEC;
214 mark_inode_dirty(inode);
215 if (error == 0)
216 acl = NULL;
217 }
218 }
219 break;
220
221 case ACL_TYPE_DEFAULT:
222 name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
223 if (!S_ISDIR(inode->i_mode))
224 return acl ? -EACCES : 0;
225 break;
226
227 default:
228 return -EINVAL;
229 }
230 if (acl) {
231 value = ext2_acl_to_disk(acl, &size);
232 if (IS_ERR(value))
233 return (int)PTR_ERR(value);
234 }
235
236 error = ext2_xattr_set(inode, name_index, "", value, size, 0);
237
238 kfree(value);
239 if (!error)
240 set_cached_acl(inode, type, acl);
241 return error;
242}
243
244
245
246
247
248
249
250int
251ext2_init_acl(struct inode *inode, struct inode *dir)
252{
253 struct posix_acl *acl = NULL;
254 int error = 0;
255
256 if (!S_ISLNK(inode->i_mode)) {
257 if (test_opt(dir->i_sb, POSIX_ACL)) {
258 acl = ext2_get_acl(dir, ACL_TYPE_DEFAULT);
259 if (IS_ERR(acl))
260 return PTR_ERR(acl);
261 }
262 if (!acl)
263 inode->i_mode &= ~current_umask();
264 }
265 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
266 if (S_ISDIR(inode->i_mode)) {
267 error = ext2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
268 if (error)
269 goto cleanup;
270 }
271 error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
272 if (error < 0)
273 return error;
274 if (error > 0) {
275
276 error = ext2_set_acl(inode, ACL_TYPE_ACCESS, acl);
277 }
278 }
279cleanup:
280 posix_acl_release(acl);
281 return error;
282}
283
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295
296
297
298int
299ext2_acl_chmod(struct inode *inode)
300{
301 struct posix_acl *acl;
302 int error;
303
304 if (!test_opt(inode->i_sb, POSIX_ACL))
305 return 0;
306 if (S_ISLNK(inode->i_mode))
307 return -EOPNOTSUPP;
308 acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
309 if (IS_ERR(acl) || !acl)
310 return PTR_ERR(acl);
311 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
312 if (error)
313 return error;
314 error = ext2_set_acl(inode, ACL_TYPE_ACCESS, acl);
315 posix_acl_release(acl);
316 return error;
317}
318
319
320
321
322static size_t
323ext2_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_size,
324 const char *name, size_t name_len, int type)
325{
326 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
327
328 if (!test_opt(dentry->d_sb, POSIX_ACL))
329 return 0;
330 if (list && size <= list_size)
331 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
332 return size;
333}
334
335static size_t
336ext2_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_size,
337 const char *name, size_t name_len, int type)
338{
339 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
340
341 if (!test_opt(dentry->d_sb, POSIX_ACL))
342 return 0;
343 if (list && size <= list_size)
344 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
345 return size;
346}
347
348static int
349ext2_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
350 size_t size, int type)
351{
352 struct posix_acl *acl;
353 int error;
354
355 if (strcmp(name, "") != 0)
356 return -EINVAL;
357 if (!test_opt(dentry->d_sb, POSIX_ACL))
358 return -EOPNOTSUPP;
359
360 acl = ext2_get_acl(dentry->d_inode, type);
361 if (IS_ERR(acl))
362 return PTR_ERR(acl);
363 if (acl == NULL)
364 return -ENODATA;
365 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
366 posix_acl_release(acl);
367
368 return error;
369}
370
371static int
372ext2_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
373 size_t size, int flags, int type)
374{
375 struct posix_acl *acl;
376 int error;
377
378 if (strcmp(name, "") != 0)
379 return -EINVAL;
380 if (!test_opt(dentry->d_sb, POSIX_ACL))
381 return -EOPNOTSUPP;
382 if (!inode_owner_or_capable(dentry->d_inode))
383 return -EPERM;
384
385 if (value) {
386 acl = posix_acl_from_xattr(&init_user_ns, value, size);
387 if (IS_ERR(acl))
388 return PTR_ERR(acl);
389 else if (acl) {
390 error = posix_acl_valid(acl);
391 if (error)
392 goto release_and_out;
393 }
394 } else
395 acl = NULL;
396
397 error = ext2_set_acl(dentry->d_inode, type, acl);
398
399release_and_out:
400 posix_acl_release(acl);
401 return error;
402}
403
404const struct xattr_handler ext2_xattr_acl_access_handler = {
405 .prefix = POSIX_ACL_XATTR_ACCESS,
406 .flags = ACL_TYPE_ACCESS,
407 .list = ext2_xattr_list_acl_access,
408 .get = ext2_xattr_get_acl,
409 .set = ext2_xattr_set_acl,
410};
411
412const struct xattr_handler ext2_xattr_acl_default_handler = {
413 .prefix = POSIX_ACL_XATTR_DEFAULT,
414 .flags = ACL_TYPE_DEFAULT,
415 .list = ext2_xattr_list_acl_default,
416 .get = ext2_xattr_get_acl,
417 .set = ext2_xattr_set_acl,
418};
419
