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1182fca3 MM |
1 | /* |
2 | * (C) 2001 Clemson University and The University of Chicago | |
3 | * | |
4 | * See COPYING in top-level directory. | |
5 | */ | |
6 | ||
7 | /* | |
8 | * Linux VFS extended attribute operations. | |
9 | */ | |
10 | ||
11 | #include "protocol.h" | |
12 | #include "pvfs2-kernel.h" | |
13 | #include "pvfs2-bufmap.h" | |
14 | #include <linux/posix_acl_xattr.h> | |
15 | #include <linux/xattr.h> | |
16 | ||
17 | ||
18 | #define SYSTEM_PVFS2_KEY "system.pvfs2." | |
19 | #define SYSTEM_PVFS2_KEY_LEN 13 | |
20 | ||
21 | /* | |
22 | * this function returns | |
23 | * 0 if the key corresponding to name is not meant to be printed as part | |
24 | * of a listxattr. | |
25 | * 1 if the key corresponding to name is meant to be returned as part of | |
26 | * a listxattr. | |
27 | * The ones that start SYSTEM_PVFS2_KEY are the ones to avoid printing. | |
28 | */ | |
29 | static int is_reserved_key(const char *key, size_t size) | |
30 | { | |
31 | ||
32 | if (size < SYSTEM_PVFS2_KEY_LEN) | |
33 | return 1; | |
34 | ||
35 | return strncmp(key, SYSTEM_PVFS2_KEY, SYSTEM_PVFS2_KEY_LEN) ? 1 : 0; | |
36 | } | |
37 | ||
38 | static inline int convert_to_internal_xattr_flags(int setxattr_flags) | |
39 | { | |
40 | int internal_flag = 0; | |
41 | ||
42 | if (setxattr_flags & XATTR_REPLACE) { | |
43 | /* Attribute must exist! */ | |
44 | internal_flag = PVFS_XATTR_REPLACE; | |
45 | } else if (setxattr_flags & XATTR_CREATE) { | |
46 | /* Attribute must not exist */ | |
47 | internal_flag = PVFS_XATTR_CREATE; | |
48 | } | |
49 | return internal_flag; | |
50 | } | |
51 | ||
52 | ||
53 | /* | |
54 | * Tries to get a specified key's attributes of a given | |
55 | * file into a user-specified buffer. Note that the getxattr | |
56 | * interface allows for the users to probe the size of an | |
57 | * extended attribute by passing in a value of 0 to size. | |
58 | * Thus our return value is always the size of the attribute | |
59 | * unless the key does not exist for the file and/or if | |
60 | * there were errors in fetching the attribute value. | |
61 | */ | |
62 | ssize_t pvfs2_inode_getxattr(struct inode *inode, const char *prefix, | |
63 | const char *name, void *buffer, size_t size) | |
64 | { | |
65 | struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode); | |
66 | struct pvfs2_kernel_op_s *new_op = NULL; | |
67 | ssize_t ret = -ENOMEM; | |
68 | ssize_t length = 0; | |
69 | int fsuid; | |
70 | int fsgid; | |
71 | ||
72 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
73 | "%s: prefix %s name %s, buffer_size %zd\n", | |
74 | __func__, prefix, name, size); | |
75 | ||
76 | if (name == NULL || (size > 0 && buffer == NULL)) { | |
77 | gossip_err("pvfs2_inode_getxattr: bogus NULL pointers\n"); | |
78 | return -EINVAL; | |
79 | } | |
eeaa3d44 MM |
80 | if ((strlen(name) + strlen(prefix)) >= PVFS_MAX_XATTR_NAMELEN) { |
81 | gossip_err("Invalid key length (%d)\n", | |
1182fca3 MM |
82 | (int)(strlen(name) + strlen(prefix))); |
83 | return -EINVAL; | |
84 | } | |
85 | ||
86 | fsuid = from_kuid(current_user_ns(), current_fsuid()); | |
87 | fsgid = from_kgid(current_user_ns(), current_fsgid()); | |
88 | ||
89 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
90 | "getxattr on inode %pU, name %s " | |
91 | "(uid %o, gid %o)\n", | |
92 | get_khandle_from_ino(inode), | |
93 | name, | |
94 | fsuid, | |
95 | fsgid); | |
96 | ||
97 | down_read(&pvfs2_inode->xattr_sem); | |
98 | ||
99 | new_op = op_alloc(PVFS2_VFS_OP_GETXATTR); | |
100 | if (!new_op) | |
101 | goto out_unlock; | |
102 | ||
103 | new_op->upcall.req.getxattr.refn = pvfs2_inode->refn; | |
104 | ret = snprintf((char *)new_op->upcall.req.getxattr.key, | |
105 | PVFS_MAX_XATTR_NAMELEN, "%s%s", prefix, name); | |
106 | ||
107 | /* | |
108 | * NOTE: Although keys are meant to be NULL terminated textual | |
109 | * strings, I am going to explicitly pass the length just in case | |
110 | * we change this later on... | |
111 | */ | |
112 | new_op->upcall.req.getxattr.key_sz = ret + 1; | |
113 | ||
114 | ret = service_operation(new_op, "pvfs2_inode_getxattr", | |
115 | get_interruptible_flag(inode)); | |
116 | if (ret != 0) { | |
117 | if (ret == -ENOENT) { | |
118 | ret = -ENODATA; | |
119 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
120 | "pvfs2_inode_getxattr: inode %pU key %s" | |
121 | " does not exist!\n", | |
122 | get_khandle_from_ino(inode), | |
123 | (char *)new_op->upcall.req.getxattr.key); | |
124 | } | |
125 | goto out_release_op; | |
126 | } | |
127 | ||
128 | /* | |
129 | * Length returned includes null terminator. | |
130 | */ | |
131 | length = new_op->downcall.resp.getxattr.val_sz; | |
132 | ||
133 | /* | |
134 | * Just return the length of the queried attribute. | |
135 | */ | |
136 | if (size == 0) { | |
137 | ret = length; | |
138 | goto out_release_op; | |
139 | } | |
140 | ||
141 | /* | |
142 | * Check to see if key length is > provided buffer size. | |
143 | */ | |
144 | if (length > size) { | |
145 | ret = -ERANGE; | |
146 | goto out_release_op; | |
147 | } | |
148 | ||
149 | memset(buffer, 0, size); | |
150 | memcpy(buffer, new_op->downcall.resp.getxattr.val, length); | |
151 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
152 | "pvfs2_inode_getxattr: inode %pU " | |
153 | "key %s key_sz %d, val_len %d\n", | |
154 | get_khandle_from_ino(inode), | |
155 | (char *)new_op-> | |
156 | upcall.req.getxattr.key, | |
157 | (int)new_op-> | |
158 | upcall.req.getxattr.key_sz, | |
159 | (int)ret); | |
160 | ||
161 | ret = length; | |
162 | ||
163 | out_release_op: | |
164 | op_release(new_op); | |
165 | out_unlock: | |
166 | up_read(&pvfs2_inode->xattr_sem); | |
167 | return ret; | |
168 | } | |
169 | ||
170 | static int pvfs2_inode_removexattr(struct inode *inode, | |
171 | const char *prefix, | |
172 | const char *name, | |
173 | int flags) | |
174 | { | |
175 | struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode); | |
176 | struct pvfs2_kernel_op_s *new_op = NULL; | |
177 | int ret = -ENOMEM; | |
178 | ||
179 | down_write(&pvfs2_inode->xattr_sem); | |
180 | new_op = op_alloc(PVFS2_VFS_OP_REMOVEXATTR); | |
181 | if (!new_op) | |
182 | goto out_unlock; | |
183 | ||
184 | new_op->upcall.req.removexattr.refn = pvfs2_inode->refn; | |
185 | /* | |
186 | * NOTE: Although keys are meant to be NULL terminated | |
187 | * textual strings, I am going to explicitly pass the | |
188 | * length just in case we change this later on... | |
189 | */ | |
190 | ret = snprintf((char *)new_op->upcall.req.removexattr.key, | |
191 | PVFS_MAX_XATTR_NAMELEN, | |
192 | "%s%s", | |
193 | (prefix ? prefix : ""), | |
194 | name); | |
195 | new_op->upcall.req.removexattr.key_sz = ret + 1; | |
196 | ||
197 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
198 | "pvfs2_inode_removexattr: key %s, key_sz %d\n", | |
199 | (char *)new_op->upcall.req.removexattr.key, | |
200 | (int)new_op->upcall.req.removexattr.key_sz); | |
201 | ||
202 | ret = service_operation(new_op, | |
203 | "pvfs2_inode_removexattr", | |
204 | get_interruptible_flag(inode)); | |
205 | if (ret == -ENOENT) { | |
206 | /* | |
207 | * Request to replace a non-existent attribute is an error. | |
208 | */ | |
209 | if (flags & XATTR_REPLACE) | |
210 | ret = -ENODATA; | |
211 | else | |
212 | ret = 0; | |
213 | } | |
214 | ||
215 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
216 | "pvfs2_inode_removexattr: returning %d\n", ret); | |
217 | ||
218 | op_release(new_op); | |
219 | out_unlock: | |
220 | up_write(&pvfs2_inode->xattr_sem); | |
221 | return ret; | |
222 | } | |
223 | ||
224 | /* | |
225 | * Tries to set an attribute for a given key on a file. | |
226 | * | |
227 | * Returns a -ve number on error and 0 on success. Key is text, but value | |
228 | * can be binary! | |
229 | */ | |
230 | int pvfs2_inode_setxattr(struct inode *inode, const char *prefix, | |
231 | const char *name, const void *value, size_t size, int flags) | |
232 | { | |
233 | struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode); | |
234 | struct pvfs2_kernel_op_s *new_op; | |
235 | int internal_flag = 0; | |
236 | int ret = -ENOMEM; | |
237 | ||
238 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
239 | "%s: prefix %s, name %s, buffer_size %zd\n", | |
240 | __func__, prefix, name, size); | |
241 | ||
242 | if (size < 0 || | |
243 | size >= PVFS_MAX_XATTR_VALUELEN || | |
244 | flags < 0) { | |
245 | gossip_err("pvfs2_inode_setxattr: bogus values of size(%d), flags(%d)\n", | |
246 | (int)size, | |
247 | flags); | |
248 | return -EINVAL; | |
249 | } | |
250 | ||
251 | if (name == NULL || | |
252 | (size > 0 && value == NULL)) { | |
253 | gossip_err("pvfs2_inode_setxattr: bogus NULL pointers!\n"); | |
254 | return -EINVAL; | |
255 | } | |
256 | ||
257 | internal_flag = convert_to_internal_xattr_flags(flags); | |
258 | ||
259 | if (prefix) { | |
260 | if (strlen(name) + strlen(prefix) >= PVFS_MAX_XATTR_NAMELEN) { | |
261 | gossip_err | |
262 | ("pvfs2_inode_setxattr: bogus key size (%d)\n", | |
263 | (int)(strlen(name) + strlen(prefix))); | |
264 | return -EINVAL; | |
265 | } | |
266 | } else { | |
267 | if (strlen(name) >= PVFS_MAX_XATTR_NAMELEN) { | |
268 | gossip_err | |
269 | ("pvfs2_inode_setxattr: bogus key size (%d)\n", | |
270 | (int)(strlen(name))); | |
271 | return -EINVAL; | |
272 | } | |
273 | } | |
274 | ||
275 | /* This is equivalent to a removexattr */ | |
276 | if (size == 0 && value == NULL) { | |
277 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
278 | "removing xattr (%s%s)\n", | |
279 | prefix, | |
280 | name); | |
281 | return pvfs2_inode_removexattr(inode, prefix, name, flags); | |
282 | } | |
283 | ||
284 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
285 | "setxattr on inode %pU, name %s\n", | |
286 | get_khandle_from_ino(inode), | |
287 | name); | |
288 | ||
289 | down_write(&pvfs2_inode->xattr_sem); | |
290 | new_op = op_alloc(PVFS2_VFS_OP_SETXATTR); | |
291 | if (!new_op) | |
292 | goto out_unlock; | |
293 | ||
294 | ||
295 | new_op->upcall.req.setxattr.refn = pvfs2_inode->refn; | |
296 | new_op->upcall.req.setxattr.flags = internal_flag; | |
297 | /* | |
298 | * NOTE: Although keys are meant to be NULL terminated textual | |
299 | * strings, I am going to explicitly pass the length just in | |
300 | * case we change this later on... | |
301 | */ | |
302 | ret = snprintf((char *)new_op->upcall.req.setxattr.keyval.key, | |
303 | PVFS_MAX_XATTR_NAMELEN, | |
304 | "%s%s", | |
305 | prefix, name); | |
306 | new_op->upcall.req.setxattr.keyval.key_sz = ret + 1; | |
307 | memcpy(new_op->upcall.req.setxattr.keyval.val, value, size); | |
308 | new_op->upcall.req.setxattr.keyval.val_sz = size; | |
309 | ||
310 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
311 | "pvfs2_inode_setxattr: key %s, key_sz %d " | |
312 | " value size %zd\n", | |
313 | (char *)new_op->upcall.req.setxattr.keyval.key, | |
314 | (int)new_op->upcall.req.setxattr.keyval.key_sz, | |
315 | size); | |
316 | ||
317 | ret = service_operation(new_op, | |
318 | "pvfs2_inode_setxattr", | |
319 | get_interruptible_flag(inode)); | |
320 | ||
321 | gossip_debug(GOSSIP_XATTR_DEBUG, | |
322 | "pvfs2_inode_setxattr: returning %d\n", | |
323 | ret); | |
324 | ||
325 | /* when request is serviced properly, free req op struct */ | |
326 | op_release(new_op); | |
327 | out_unlock: | |
328 | up_write(&pvfs2_inode->xattr_sem); | |
329 | return ret; | |
330 | } | |
331 | ||
332 | /* | |
333 | * Tries to get a specified object's keys into a user-specified buffer of a | |
334 | * given size. Note that like the previous instances of xattr routines, this | |
335 | * also allows you to pass in a NULL pointer and 0 size to probe the size for | |
336 | * subsequent memory allocations. Thus our return value is always the size of | |
337 | * all the keys unless there were errors in fetching the keys! | |
338 | */ | |
339 | ssize_t pvfs2_listxattr(struct dentry *dentry, char *buffer, size_t size) | |
340 | { | |
341 | struct inode *inode = dentry->d_inode; | |
342 | struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode); | |
343 | struct pvfs2_kernel_op_s *new_op; | |
344 | __u64 token = PVFS_ITERATE_START; | |
345 | ssize_t ret = -ENOMEM; | |
346 | ssize_t total = 0; | |
347 | ssize_t length = 0; | |
348 | int count_keys = 0; | |
349 | int key_size; | |
350 | int i = 0; | |
351 | ||
352 | if (size > 0 && buffer == NULL) { | |
353 | gossip_err("%s: bogus NULL pointers\n", __func__); | |
354 | return -EINVAL; | |
355 | } | |
356 | if (size < 0) { | |
357 | gossip_err("Invalid size (%d)\n", (int)size); | |
358 | return -EINVAL; | |
359 | } | |
360 | ||
361 | down_read(&pvfs2_inode->xattr_sem); | |
362 | new_op = op_alloc(PVFS2_VFS_OP_LISTXATTR); | |
363 | if (!new_op) | |
364 | goto out_unlock; | |
365 | ||
366 | if (buffer && size > 0) | |
367 | memset(buffer, 0, size); | |
368 | ||
369 | try_again: | |
370 | key_size = 0; | |
371 | new_op->upcall.req.listxattr.refn = pvfs2_inode->refn; | |
372 | new_op->upcall.req.listxattr.token = token; | |
373 | new_op->upcall.req.listxattr.requested_count = | |
374 | (size == 0) ? 0 : PVFS_MAX_XATTR_LISTLEN; | |
375 | ret = service_operation(new_op, __func__, | |
376 | get_interruptible_flag(inode)); | |
377 | if (ret != 0) | |
378 | goto done; | |
379 | ||
380 | if (size == 0) { | |
381 | /* | |
382 | * This is a bit of a big upper limit, but I did not want to | |
383 | * spend too much time getting this correct, since users end | |
384 | * up allocating memory rather than us... | |
385 | */ | |
386 | total = new_op->downcall.resp.listxattr.returned_count * | |
387 | PVFS_MAX_XATTR_NAMELEN; | |
388 | goto done; | |
389 | } | |
390 | ||
391 | length = new_op->downcall.resp.listxattr.keylen; | |
392 | if (length == 0) | |
393 | goto done; | |
394 | ||
395 | /* | |
396 | * Check to see how much can be fit in the buffer. Fit only whole keys. | |
397 | */ | |
398 | for (i = 0; i < new_op->downcall.resp.listxattr.returned_count; i++) { | |
399 | if (total + new_op->downcall.resp.listxattr.lengths[i] > size) | |
400 | goto done; | |
401 | ||
402 | /* | |
403 | * Since many dumb programs try to setxattr() on our reserved | |
404 | * xattrs this is a feeble attempt at defeating those by not | |
405 | * listing them in the output of listxattr.. sigh | |
406 | */ | |
407 | if (is_reserved_key(new_op->downcall.resp.listxattr.key + | |
408 | key_size, | |
409 | new_op->downcall.resp. | |
410 | listxattr.lengths[i])) { | |
411 | gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n", | |
412 | i, new_op->downcall.resp.listxattr.key + | |
413 | key_size); | |
414 | memcpy(buffer + total, | |
415 | new_op->downcall.resp.listxattr.key + key_size, | |
416 | new_op->downcall.resp.listxattr.lengths[i]); | |
417 | total += new_op->downcall.resp.listxattr.lengths[i]; | |
418 | count_keys++; | |
419 | } else { | |
420 | gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n", | |
421 | i, new_op->downcall.resp.listxattr.key + | |
422 | key_size); | |
423 | } | |
424 | key_size += new_op->downcall.resp.listxattr.lengths[i]; | |
425 | } | |
426 | ||
427 | /* | |
428 | * Since the buffer was large enough, we might have to continue | |
429 | * fetching more keys! | |
430 | */ | |
431 | token = new_op->downcall.resp.listxattr.token; | |
432 | if (token != PVFS_ITERATE_END) | |
433 | goto try_again; | |
434 | ||
435 | done: | |
436 | gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d" | |
437 | " [size of buffer %ld] (filled in %d keys)\n", | |
438 | __func__, | |
439 | ret ? (int)ret : (int)total, | |
440 | (long)size, | |
441 | count_keys); | |
442 | op_release(new_op); | |
443 | if (ret == 0) | |
444 | ret = total; | |
445 | out_unlock: | |
446 | up_read(&pvfs2_inode->xattr_sem); | |
447 | return ret; | |
448 | } | |
449 | ||
555fa0fa AV |
450 | static int pvfs2_xattr_set_default(const struct xattr_handler *handler, |
451 | struct dentry *dentry, | |
452 | const char *name, | |
453 | const void *buffer, | |
454 | size_t size, | |
455 | int flags) | |
1182fca3 MM |
456 | { |
457 | return pvfs2_inode_setxattr(dentry->d_inode, | |
458 | PVFS2_XATTR_NAME_DEFAULT_PREFIX, | |
459 | name, | |
460 | buffer, | |
461 | size, | |
462 | flags); | |
463 | } | |
464 | ||
555fa0fa AV |
465 | static int pvfs2_xattr_get_default(const struct xattr_handler *handler, |
466 | struct dentry *dentry, | |
467 | const char *name, | |
468 | void *buffer, | |
469 | size_t size) | |
1182fca3 MM |
470 | { |
471 | return pvfs2_inode_getxattr(dentry->d_inode, | |
472 | PVFS2_XATTR_NAME_DEFAULT_PREFIX, | |
473 | name, | |
474 | buffer, | |
475 | size); | |
476 | ||
477 | } | |
478 | ||
555fa0fa AV |
479 | static int pvfs2_xattr_set_trusted(const struct xattr_handler *handler, |
480 | struct dentry *dentry, | |
481 | const char *name, | |
482 | const void *buffer, | |
483 | size_t size, | |
484 | int flags) | |
1182fca3 MM |
485 | { |
486 | return pvfs2_inode_setxattr(dentry->d_inode, | |
487 | PVFS2_XATTR_NAME_TRUSTED_PREFIX, | |
488 | name, | |
489 | buffer, | |
490 | size, | |
491 | flags); | |
492 | } | |
493 | ||
555fa0fa AV |
494 | static int pvfs2_xattr_get_trusted(const struct xattr_handler *handler, |
495 | struct dentry *dentry, | |
496 | const char *name, | |
497 | void *buffer, | |
498 | size_t size) | |
1182fca3 MM |
499 | { |
500 | return pvfs2_inode_getxattr(dentry->d_inode, | |
501 | PVFS2_XATTR_NAME_TRUSTED_PREFIX, | |
502 | name, | |
503 | buffer, | |
504 | size); | |
505 | } | |
506 | ||
507 | static struct xattr_handler pvfs2_xattr_trusted_handler = { | |
508 | .prefix = PVFS2_XATTR_NAME_TRUSTED_PREFIX, | |
509 | .get = pvfs2_xattr_get_trusted, | |
510 | .set = pvfs2_xattr_set_trusted, | |
511 | }; | |
512 | ||
513 | static struct xattr_handler pvfs2_xattr_default_handler = { | |
514 | /* | |
515 | * NOTE: this is set to be the empty string. | |
516 | * so that all un-prefixed xattrs keys get caught | |
517 | * here! | |
518 | */ | |
519 | .prefix = PVFS2_XATTR_NAME_DEFAULT_PREFIX, | |
520 | .get = pvfs2_xattr_get_default, | |
521 | .set = pvfs2_xattr_set_default, | |
522 | }; | |
523 | ||
524 | const struct xattr_handler *pvfs2_xattr_handlers[] = { | |
525 | &posix_acl_access_xattr_handler, | |
526 | &posix_acl_default_xattr_handler, | |
527 | &pvfs2_xattr_trusted_handler, | |
528 | &pvfs2_xattr_default_handler, | |
529 | NULL | |
530 | }; |