diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/xattr.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/xattr.c')
-rw-r--r-- | fs/xattr.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/fs/xattr.c b/fs/xattr.c new file mode 100644 index 000000000000..93dee70a1dbe --- /dev/null +++ b/fs/xattr.c | |||
@@ -0,0 +1,480 @@ | |||
1 | /* | ||
2 | File: fs/xattr.c | ||
3 | |||
4 | Extended attribute handling. | ||
5 | |||
6 | Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> | ||
7 | Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com> | ||
8 | Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> | ||
9 | */ | ||
10 | #include <linux/fs.h> | ||
11 | #include <linux/slab.h> | ||
12 | #include <linux/smp_lock.h> | ||
13 | #include <linux/file.h> | ||
14 | #include <linux/xattr.h> | ||
15 | #include <linux/namei.h> | ||
16 | #include <linux/security.h> | ||
17 | #include <linux/syscalls.h> | ||
18 | #include <linux/module.h> | ||
19 | #include <asm/uaccess.h> | ||
20 | |||
21 | /* | ||
22 | * Extended attribute SET operations | ||
23 | */ | ||
24 | static long | ||
25 | setxattr(struct dentry *d, char __user *name, void __user *value, | ||
26 | size_t size, int flags) | ||
27 | { | ||
28 | int error; | ||
29 | void *kvalue = NULL; | ||
30 | char kname[XATTR_NAME_MAX + 1]; | ||
31 | |||
32 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) | ||
33 | return -EINVAL; | ||
34 | |||
35 | error = strncpy_from_user(kname, name, sizeof(kname)); | ||
36 | if (error == 0 || error == sizeof(kname)) | ||
37 | error = -ERANGE; | ||
38 | if (error < 0) | ||
39 | return error; | ||
40 | |||
41 | if (size) { | ||
42 | if (size > XATTR_SIZE_MAX) | ||
43 | return -E2BIG; | ||
44 | kvalue = kmalloc(size, GFP_KERNEL); | ||
45 | if (!kvalue) | ||
46 | return -ENOMEM; | ||
47 | if (copy_from_user(kvalue, value, size)) { | ||
48 | kfree(kvalue); | ||
49 | return -EFAULT; | ||
50 | } | ||
51 | } | ||
52 | |||
53 | error = -EOPNOTSUPP; | ||
54 | if (d->d_inode->i_op && d->d_inode->i_op->setxattr) { | ||
55 | down(&d->d_inode->i_sem); | ||
56 | error = security_inode_setxattr(d, kname, kvalue, size, flags); | ||
57 | if (error) | ||
58 | goto out; | ||
59 | error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags); | ||
60 | if (!error) | ||
61 | security_inode_post_setxattr(d, kname, kvalue, size, flags); | ||
62 | out: | ||
63 | up(&d->d_inode->i_sem); | ||
64 | } | ||
65 | if (kvalue) | ||
66 | kfree(kvalue); | ||
67 | return error; | ||
68 | } | ||
69 | |||
70 | asmlinkage long | ||
71 | sys_setxattr(char __user *path, char __user *name, void __user *value, | ||
72 | size_t size, int flags) | ||
73 | { | ||
74 | struct nameidata nd; | ||
75 | int error; | ||
76 | |||
77 | error = user_path_walk(path, &nd); | ||
78 | if (error) | ||
79 | return error; | ||
80 | error = setxattr(nd.dentry, name, value, size, flags); | ||
81 | path_release(&nd); | ||
82 | return error; | ||
83 | } | ||
84 | |||
85 | asmlinkage long | ||
86 | sys_lsetxattr(char __user *path, char __user *name, void __user *value, | ||
87 | size_t size, int flags) | ||
88 | { | ||
89 | struct nameidata nd; | ||
90 | int error; | ||
91 | |||
92 | error = user_path_walk_link(path, &nd); | ||
93 | if (error) | ||
94 | return error; | ||
95 | error = setxattr(nd.dentry, name, value, size, flags); | ||
96 | path_release(&nd); | ||
97 | return error; | ||
98 | } | ||
99 | |||
100 | asmlinkage long | ||
101 | sys_fsetxattr(int fd, char __user *name, void __user *value, | ||
102 | size_t size, int flags) | ||
103 | { | ||
104 | struct file *f; | ||
105 | int error = -EBADF; | ||
106 | |||
107 | f = fget(fd); | ||
108 | if (!f) | ||
109 | return error; | ||
110 | error = setxattr(f->f_dentry, name, value, size, flags); | ||
111 | fput(f); | ||
112 | return error; | ||
113 | } | ||
114 | |||
115 | /* | ||
116 | * Extended attribute GET operations | ||
117 | */ | ||
118 | static ssize_t | ||
119 | getxattr(struct dentry *d, char __user *name, void __user *value, size_t size) | ||
120 | { | ||
121 | ssize_t error; | ||
122 | void *kvalue = NULL; | ||
123 | char kname[XATTR_NAME_MAX + 1]; | ||
124 | |||
125 | error = strncpy_from_user(kname, name, sizeof(kname)); | ||
126 | if (error == 0 || error == sizeof(kname)) | ||
127 | error = -ERANGE; | ||
128 | if (error < 0) | ||
129 | return error; | ||
130 | |||
131 | if (size) { | ||
132 | if (size > XATTR_SIZE_MAX) | ||
133 | size = XATTR_SIZE_MAX; | ||
134 | kvalue = kmalloc(size, GFP_KERNEL); | ||
135 | if (!kvalue) | ||
136 | return -ENOMEM; | ||
137 | } | ||
138 | |||
139 | error = -EOPNOTSUPP; | ||
140 | if (d->d_inode->i_op && d->d_inode->i_op->getxattr) { | ||
141 | error = security_inode_getxattr(d, kname); | ||
142 | if (error) | ||
143 | goto out; | ||
144 | error = d->d_inode->i_op->getxattr(d, kname, kvalue, size); | ||
145 | if (error > 0) { | ||
146 | if (size && copy_to_user(value, kvalue, error)) | ||
147 | error = -EFAULT; | ||
148 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { | ||
149 | /* The file system tried to returned a value bigger | ||
150 | than XATTR_SIZE_MAX bytes. Not possible. */ | ||
151 | error = -E2BIG; | ||
152 | } | ||
153 | } | ||
154 | out: | ||
155 | if (kvalue) | ||
156 | kfree(kvalue); | ||
157 | return error; | ||
158 | } | ||
159 | |||
160 | asmlinkage ssize_t | ||
161 | sys_getxattr(char __user *path, char __user *name, void __user *value, | ||
162 | size_t size) | ||
163 | { | ||
164 | struct nameidata nd; | ||
165 | ssize_t error; | ||
166 | |||
167 | error = user_path_walk(path, &nd); | ||
168 | if (error) | ||
169 | return error; | ||
170 | error = getxattr(nd.dentry, name, value, size); | ||
171 | path_release(&nd); | ||
172 | return error; | ||
173 | } | ||
174 | |||
175 | asmlinkage ssize_t | ||
176 | sys_lgetxattr(char __user *path, char __user *name, void __user *value, | ||
177 | size_t size) | ||
178 | { | ||
179 | struct nameidata nd; | ||
180 | ssize_t error; | ||
181 | |||
182 | error = user_path_walk_link(path, &nd); | ||
183 | if (error) | ||
184 | return error; | ||
185 | error = getxattr(nd.dentry, name, value, size); | ||
186 | path_release(&nd); | ||
187 | return error; | ||
188 | } | ||
189 | |||
190 | asmlinkage ssize_t | ||
191 | sys_fgetxattr(int fd, char __user *name, void __user *value, size_t size) | ||
192 | { | ||
193 | struct file *f; | ||
194 | ssize_t error = -EBADF; | ||
195 | |||
196 | f = fget(fd); | ||
197 | if (!f) | ||
198 | return error; | ||
199 | error = getxattr(f->f_dentry, name, value, size); | ||
200 | fput(f); | ||
201 | return error; | ||
202 | } | ||
203 | |||
204 | /* | ||
205 | * Extended attribute LIST operations | ||
206 | */ | ||
207 | static ssize_t | ||
208 | listxattr(struct dentry *d, char __user *list, size_t size) | ||
209 | { | ||
210 | ssize_t error; | ||
211 | char *klist = NULL; | ||
212 | |||
213 | if (size) { | ||
214 | if (size > XATTR_LIST_MAX) | ||
215 | size = XATTR_LIST_MAX; | ||
216 | klist = kmalloc(size, GFP_KERNEL); | ||
217 | if (!klist) | ||
218 | return -ENOMEM; | ||
219 | } | ||
220 | |||
221 | error = -EOPNOTSUPP; | ||
222 | if (d->d_inode->i_op && d->d_inode->i_op->listxattr) { | ||
223 | error = security_inode_listxattr(d); | ||
224 | if (error) | ||
225 | goto out; | ||
226 | error = d->d_inode->i_op->listxattr(d, klist, size); | ||
227 | if (error > 0) { | ||
228 | if (size && copy_to_user(list, klist, error)) | ||
229 | error = -EFAULT; | ||
230 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { | ||
231 | /* The file system tried to returned a list bigger | ||
232 | than XATTR_LIST_MAX bytes. Not possible. */ | ||
233 | error = -E2BIG; | ||
234 | } | ||
235 | } | ||
236 | out: | ||
237 | if (klist) | ||
238 | kfree(klist); | ||
239 | return error; | ||
240 | } | ||
241 | |||
242 | asmlinkage ssize_t | ||
243 | sys_listxattr(char __user *path, char __user *list, size_t size) | ||
244 | { | ||
245 | struct nameidata nd; | ||
246 | ssize_t error; | ||
247 | |||
248 | error = user_path_walk(path, &nd); | ||
249 | if (error) | ||
250 | return error; | ||
251 | error = listxattr(nd.dentry, list, size); | ||
252 | path_release(&nd); | ||
253 | return error; | ||
254 | } | ||
255 | |||
256 | asmlinkage ssize_t | ||
257 | sys_llistxattr(char __user *path, char __user *list, size_t size) | ||
258 | { | ||
259 | struct nameidata nd; | ||
260 | ssize_t error; | ||
261 | |||
262 | error = user_path_walk_link(path, &nd); | ||
263 | if (error) | ||
264 | return error; | ||
265 | error = listxattr(nd.dentry, list, size); | ||
266 | path_release(&nd); | ||
267 | return error; | ||
268 | } | ||
269 | |||
270 | asmlinkage ssize_t | ||
271 | sys_flistxattr(int fd, char __user *list, size_t size) | ||
272 | { | ||
273 | struct file *f; | ||
274 | ssize_t error = -EBADF; | ||
275 | |||
276 | f = fget(fd); | ||
277 | if (!f) | ||
278 | return error; | ||
279 | error = listxattr(f->f_dentry, list, size); | ||
280 | fput(f); | ||
281 | return error; | ||
282 | } | ||
283 | |||
284 | /* | ||
285 | * Extended attribute REMOVE operations | ||
286 | */ | ||
287 | static long | ||
288 | removexattr(struct dentry *d, char __user *name) | ||
289 | { | ||
290 | int error; | ||
291 | char kname[XATTR_NAME_MAX + 1]; | ||
292 | |||
293 | error = strncpy_from_user(kname, name, sizeof(kname)); | ||
294 | if (error == 0 || error == sizeof(kname)) | ||
295 | error = -ERANGE; | ||
296 | if (error < 0) | ||
297 | return error; | ||
298 | |||
299 | error = -EOPNOTSUPP; | ||
300 | if (d->d_inode->i_op && d->d_inode->i_op->removexattr) { | ||
301 | error = security_inode_removexattr(d, kname); | ||
302 | if (error) | ||
303 | goto out; | ||
304 | down(&d->d_inode->i_sem); | ||
305 | error = d->d_inode->i_op->removexattr(d, kname); | ||
306 | up(&d->d_inode->i_sem); | ||
307 | } | ||
308 | out: | ||
309 | return error; | ||
310 | } | ||
311 | |||
312 | asmlinkage long | ||
313 | sys_removexattr(char __user *path, char __user *name) | ||
314 | { | ||
315 | struct nameidata nd; | ||
316 | int error; | ||
317 | |||
318 | error = user_path_walk(path, &nd); | ||
319 | if (error) | ||
320 | return error; | ||
321 | error = removexattr(nd.dentry, name); | ||
322 | path_release(&nd); | ||
323 | return error; | ||
324 | } | ||
325 | |||
326 | asmlinkage long | ||
327 | sys_lremovexattr(char __user *path, char __user *name) | ||
328 | { | ||
329 | struct nameidata nd; | ||
330 | int error; | ||
331 | |||
332 | error = user_path_walk_link(path, &nd); | ||
333 | if (error) | ||
334 | return error; | ||
335 | error = removexattr(nd.dentry, name); | ||
336 | path_release(&nd); | ||
337 | return error; | ||
338 | } | ||
339 | |||
340 | asmlinkage long | ||
341 | sys_fremovexattr(int fd, char __user *name) | ||
342 | { | ||
343 | struct file *f; | ||
344 | int error = -EBADF; | ||
345 | |||
346 | f = fget(fd); | ||
347 | if (!f) | ||
348 | return error; | ||
349 | error = removexattr(f->f_dentry, name); | ||
350 | fput(f); | ||
351 | return error; | ||
352 | } | ||
353 | |||
354 | |||
355 | static const char * | ||
356 | strcmp_prefix(const char *a, const char *a_prefix) | ||
357 | { | ||
358 | while (*a_prefix && *a == *a_prefix) { | ||
359 | a++; | ||
360 | a_prefix++; | ||
361 | } | ||
362 | return *a_prefix ? NULL : a; | ||
363 | } | ||
364 | |||
365 | /* | ||
366 | * In order to implement different sets of xattr operations for each xattr | ||
367 | * prefix with the generic xattr API, a filesystem should create a | ||
368 | * null-terminated array of struct xattr_handler (one for each prefix) and | ||
369 | * hang a pointer to it off of the s_xattr field of the superblock. | ||
370 | * | ||
371 | * The generic_fooxattr() functions will use this list to dispatch xattr | ||
372 | * operations to the correct xattr_handler. | ||
373 | */ | ||
374 | #define for_each_xattr_handler(handlers, handler) \ | ||
375 | for ((handler) = *(handlers)++; \ | ||
376 | (handler) != NULL; \ | ||
377 | (handler) = *(handlers)++) | ||
378 | |||
379 | /* | ||
380 | * Find the xattr_handler with the matching prefix. | ||
381 | */ | ||
382 | static struct xattr_handler * | ||
383 | xattr_resolve_name(struct xattr_handler **handlers, const char **name) | ||
384 | { | ||
385 | struct xattr_handler *handler; | ||
386 | |||
387 | if (!*name) | ||
388 | return NULL; | ||
389 | |||
390 | for_each_xattr_handler(handlers, handler) { | ||
391 | const char *n = strcmp_prefix(*name, handler->prefix); | ||
392 | if (n) { | ||
393 | *name = n; | ||
394 | break; | ||
395 | } | ||
396 | } | ||
397 | return handler; | ||
398 | } | ||
399 | |||
400 | /* | ||
401 | * Find the handler for the prefix and dispatch its get() operation. | ||
402 | */ | ||
403 | ssize_t | ||
404 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) | ||
405 | { | ||
406 | struct xattr_handler *handler; | ||
407 | struct inode *inode = dentry->d_inode; | ||
408 | |||
409 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | ||
410 | if (!handler) | ||
411 | return -EOPNOTSUPP; | ||
412 | return handler->get(inode, name, buffer, size); | ||
413 | } | ||
414 | |||
415 | /* | ||
416 | * Combine the results of the list() operation from every xattr_handler in the | ||
417 | * list. | ||
418 | */ | ||
419 | ssize_t | ||
420 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) | ||
421 | { | ||
422 | struct inode *inode = dentry->d_inode; | ||
423 | struct xattr_handler *handler, **handlers = inode->i_sb->s_xattr; | ||
424 | unsigned int size = 0; | ||
425 | |||
426 | if (!buffer) { | ||
427 | for_each_xattr_handler(handlers, handler) | ||
428 | size += handler->list(inode, NULL, 0, NULL, 0); | ||
429 | } else { | ||
430 | char *buf = buffer; | ||
431 | |||
432 | for_each_xattr_handler(handlers, handler) { | ||
433 | size = handler->list(inode, buf, buffer_size, NULL, 0); | ||
434 | if (size > buffer_size) | ||
435 | return -ERANGE; | ||
436 | buf += size; | ||
437 | buffer_size -= size; | ||
438 | } | ||
439 | size = buf - buffer; | ||
440 | } | ||
441 | return size; | ||
442 | } | ||
443 | |||
444 | /* | ||
445 | * Find the handler for the prefix and dispatch its set() operation. | ||
446 | */ | ||
447 | int | ||
448 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) | ||
449 | { | ||
450 | struct xattr_handler *handler; | ||
451 | struct inode *inode = dentry->d_inode; | ||
452 | |||
453 | if (size == 0) | ||
454 | value = ""; /* empty EA, do not remove */ | ||
455 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | ||
456 | if (!handler) | ||
457 | return -EOPNOTSUPP; | ||
458 | return handler->set(inode, name, value, size, flags); | ||
459 | } | ||
460 | |||
461 | /* | ||
462 | * Find the handler for the prefix and dispatch its set() operation to remove | ||
463 | * any associated extended attribute. | ||
464 | */ | ||
465 | int | ||
466 | generic_removexattr(struct dentry *dentry, const char *name) | ||
467 | { | ||
468 | struct xattr_handler *handler; | ||
469 | struct inode *inode = dentry->d_inode; | ||
470 | |||
471 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | ||
472 | if (!handler) | ||
473 | return -EOPNOTSUPP; | ||
474 | return handler->set(inode, name, NULL, 0, XATTR_REPLACE); | ||
475 | } | ||
476 | |||
477 | EXPORT_SYMBOL(generic_getxattr); | ||
478 | EXPORT_SYMBOL(generic_listxattr); | ||
479 | EXPORT_SYMBOL(generic_setxattr); | ||
480 | EXPORT_SYMBOL(generic_removexattr); | ||