1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * (C) 2001 Clemson University and The University of Chicago
4 * Copyright 2018 Omnibond Systems, L.L.C.
5 *
6 * See COPYING in top-level directory.
7 */
8
9 /*
10 * Linux VFS extended attribute operations.
11 */
12
13 #include "protocol.h"
14 #include "orangefs-kernel.h"
15 #include "orangefs-bufmap.h"
16 #include <linux/posix_acl_xattr.h>
17 #include <linux/xattr.h>
18 #include <linux/hashtable.h>
19
20 #define SYSTEM_ORANGEFS_KEY "system.pvfs2."
21 #define SYSTEM_ORANGEFS_KEY_LEN 13
22
23 /*
24 * this function returns
25 * 0 if the key corresponding to name is not meant to be printed as part
26 * of a listxattr.
27 * 1 if the key corresponding to name is meant to be returned as part of
28 * a listxattr.
29 * The ones that start SYSTEM_ORANGEFS_KEY are the ones to avoid printing.
30 */
is_reserved_key(const char * key,size_t size)31 static int is_reserved_key(const char *key, size_t size)
32 {
33
34 if (size < SYSTEM_ORANGEFS_KEY_LEN)
35 return 1;
36
37 return strncmp(key, SYSTEM_ORANGEFS_KEY, SYSTEM_ORANGEFS_KEY_LEN) ? 1 : 0;
38 }
39
convert_to_internal_xattr_flags(int setxattr_flags)40 static inline int convert_to_internal_xattr_flags(int setxattr_flags)
41 {
42 int internal_flag = 0;
43
44 if (setxattr_flags & XATTR_REPLACE) {
45 /* Attribute must exist! */
46 internal_flag = ORANGEFS_XATTR_REPLACE;
47 } else if (setxattr_flags & XATTR_CREATE) {
48 /* Attribute must not exist */
49 internal_flag = ORANGEFS_XATTR_CREATE;
50 }
51 return internal_flag;
52 }
53
xattr_key(const char * key)54 static unsigned int xattr_key(const char *key)
55 {
56 unsigned int i = 0;
57 while (key)
58 i += *key++;
59 return i % 16;
60 }
61
find_cached_xattr(struct inode * inode,const char * key)62 static struct orangefs_cached_xattr *find_cached_xattr(struct inode *inode,
63 const char *key)
64 {
65 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
66 struct orangefs_cached_xattr *cx;
67 struct hlist_head *h;
68 struct hlist_node *tmp;
69 h = &orangefs_inode->xattr_cache[xattr_key(key)];
70 if (hlist_empty(h))
71 return NULL;
72 hlist_for_each_entry_safe(cx, tmp, h, node) {
73 /* if (!time_before(jiffies, cx->timeout)) {
74 hlist_del(&cx->node);
75 kfree(cx);
76 continue;
77 }*/
78 if (!strcmp(cx->key, key))
79 return cx;
80 }
81 return NULL;
82 }
83
84 /*
85 * Tries to get a specified key's attributes of a given
86 * file into a user-specified buffer. Note that the getxattr
87 * interface allows for the users to probe the size of an
88 * extended attribute by passing in a value of 0 to size.
89 * Thus our return value is always the size of the attribute
90 * unless the key does not exist for the file and/or if
91 * there were errors in fetching the attribute value.
92 */
orangefs_inode_getxattr(struct inode * inode,const char * name,void * buffer,size_t size)93 ssize_t orangefs_inode_getxattr(struct inode *inode, const char *name,
94 void *buffer, size_t size)
95 {
96 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
97 struct orangefs_kernel_op_s *new_op = NULL;
98 struct orangefs_cached_xattr *cx;
99 ssize_t ret = -ENOMEM;
100 ssize_t length = 0;
101 int fsuid;
102 int fsgid;
103
104 gossip_debug(GOSSIP_XATTR_DEBUG,
105 "%s: name %s, buffer_size %zd\n",
106 __func__, name, size);
107
108 if (S_ISLNK(inode->i_mode))
109 return -EOPNOTSUPP;
110
111 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
112 return -EINVAL;
113
114 fsuid = from_kuid(&init_user_ns, current_fsuid());
115 fsgid = from_kgid(&init_user_ns, current_fsgid());
116
117 gossip_debug(GOSSIP_XATTR_DEBUG,
118 "getxattr on inode %pU, name %s "
119 "(uid %o, gid %o)\n",
120 get_khandle_from_ino(inode),
121 name,
122 fsuid,
123 fsgid);
124
125 down_read(&orangefs_inode->xattr_sem);
126
127 cx = find_cached_xattr(inode, name);
128 if (cx && time_before(jiffies, cx->timeout)) {
129 if (cx->length == -1) {
130 ret = -ENODATA;
131 goto out_unlock;
132 } else {
133 if (size == 0) {
134 ret = cx->length;
135 goto out_unlock;
136 }
137 if (cx->length > size) {
138 ret = -ERANGE;
139 goto out_unlock;
140 }
141 memcpy(buffer, cx->val, cx->length);
142 memset(buffer + cx->length, 0, size - cx->length);
143 ret = cx->length;
144 goto out_unlock;
145 }
146 }
147
148 new_op = op_alloc(ORANGEFS_VFS_OP_GETXATTR);
149 if (!new_op)
150 goto out_unlock;
151
152 new_op->upcall.req.getxattr.refn = orangefs_inode->refn;
153 strcpy(new_op->upcall.req.getxattr.key, name);
154
155 /*
156 * NOTE: Although keys are meant to be NULL terminated textual
157 * strings, I am going to explicitly pass the length just in case
158 * we change this later on...
159 */
160 new_op->upcall.req.getxattr.key_sz = strlen(name) + 1;
161
162 ret = service_operation(new_op, "orangefs_inode_getxattr",
163 get_interruptible_flag(inode));
164 if (ret != 0) {
165 if (ret == -ENOENT) {
166 ret = -ENODATA;
167 gossip_debug(GOSSIP_XATTR_DEBUG,
168 "orangefs_inode_getxattr: inode %pU key %s"
169 " does not exist!\n",
170 get_khandle_from_ino(inode),
171 (char *)new_op->upcall.req.getxattr.key);
172 cx = kmalloc(sizeof *cx, GFP_KERNEL);
173 if (cx) {
174 strcpy(cx->key, name);
175 cx->length = -1;
176 cx->timeout = jiffies +
177 orangefs_getattr_timeout_msecs*HZ/1000;
178 hash_add(orangefs_inode->xattr_cache, &cx->node,
179 xattr_key(cx->key));
180 }
181 }
182 goto out_release_op;
183 }
184
185 /*
186 * Length returned includes null terminator.
187 */
188 length = new_op->downcall.resp.getxattr.val_sz;
189
190 /*
191 * Just return the length of the queried attribute.
192 */
193 if (size == 0) {
194 ret = length;
195 goto out_release_op;
196 }
197
198 /*
199 * Check to see if key length is > provided buffer size.
200 */
201 if (length > size) {
202 ret = -ERANGE;
203 goto out_release_op;
204 }
205
206 memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
207 memset(buffer + length, 0, size - length);
208 gossip_debug(GOSSIP_XATTR_DEBUG,
209 "orangefs_inode_getxattr: inode %pU "
210 "key %s key_sz %d, val_len %d\n",
211 get_khandle_from_ino(inode),
212 (char *)new_op->
213 upcall.req.getxattr.key,
214 (int)new_op->
215 upcall.req.getxattr.key_sz,
216 (int)ret);
217
218 ret = length;
219
220 if (cx) {
221 strcpy(cx->key, name);
222 memcpy(cx->val, buffer, length);
223 cx->length = length;
224 cx->timeout = jiffies + HZ;
225 } else {
226 cx = kmalloc(sizeof *cx, GFP_KERNEL);
227 if (cx) {
228 strcpy(cx->key, name);
229 memcpy(cx->val, buffer, length);
230 cx->length = length;
231 cx->timeout = jiffies + HZ;
232 hash_add(orangefs_inode->xattr_cache, &cx->node,
233 xattr_key(cx->key));
234 }
235 }
236
237 out_release_op:
238 op_release(new_op);
239 out_unlock:
240 up_read(&orangefs_inode->xattr_sem);
241 return ret;
242 }
243
orangefs_inode_removexattr(struct inode * inode,const char * name,int flags)244 static int orangefs_inode_removexattr(struct inode *inode, const char *name,
245 int flags)
246 {
247 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
248 struct orangefs_kernel_op_s *new_op = NULL;
249 struct orangefs_cached_xattr *cx;
250 struct hlist_head *h;
251 struct hlist_node *tmp;
252 int ret = -ENOMEM;
253
254 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
255 return -EINVAL;
256
257 down_write(&orangefs_inode->xattr_sem);
258 new_op = op_alloc(ORANGEFS_VFS_OP_REMOVEXATTR);
259 if (!new_op)
260 goto out_unlock;
261
262 new_op->upcall.req.removexattr.refn = orangefs_inode->refn;
263 /*
264 * NOTE: Although keys are meant to be NULL terminated
265 * textual strings, I am going to explicitly pass the
266 * length just in case we change this later on...
267 */
268 strcpy(new_op->upcall.req.removexattr.key, name);
269 new_op->upcall.req.removexattr.key_sz = strlen(name) + 1;
270
271 gossip_debug(GOSSIP_XATTR_DEBUG,
272 "orangefs_inode_removexattr: key %s, key_sz %d\n",
273 (char *)new_op->upcall.req.removexattr.key,
274 (int)new_op->upcall.req.removexattr.key_sz);
275
276 ret = service_operation(new_op,
277 "orangefs_inode_removexattr",
278 get_interruptible_flag(inode));
279 if (ret == -ENOENT) {
280 /*
281 * Request to replace a non-existent attribute is an error.
282 */
283 if (flags & XATTR_REPLACE)
284 ret = -ENODATA;
285 else
286 ret = 0;
287 }
288
289 gossip_debug(GOSSIP_XATTR_DEBUG,
290 "orangefs_inode_removexattr: returning %d\n", ret);
291
292 op_release(new_op);
293
294 h = &orangefs_inode->xattr_cache[xattr_key(name)];
295 hlist_for_each_entry_safe(cx, tmp, h, node) {
296 if (!strcmp(cx->key, name)) {
297 hlist_del(&cx->node);
298 kfree(cx);
299 break;
300 }
301 }
302
303 out_unlock:
304 up_write(&orangefs_inode->xattr_sem);
305 return ret;
306 }
307
308 /*
309 * Tries to set an attribute for a given key on a file.
310 *
311 * Returns a -ve number on error and 0 on success. Key is text, but value
312 * can be binary!
313 */
orangefs_inode_setxattr(struct inode * inode,const char * name,const void * value,size_t size,int flags)314 int orangefs_inode_setxattr(struct inode *inode, const char *name,
315 const void *value, size_t size, int flags)
316 {
317 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
318 struct orangefs_kernel_op_s *new_op;
319 int internal_flag = 0;
320 struct orangefs_cached_xattr *cx;
321 struct hlist_head *h;
322 struct hlist_node *tmp;
323 int ret = -ENOMEM;
324
325 gossip_debug(GOSSIP_XATTR_DEBUG,
326 "%s: name %s, buffer_size %zd\n",
327 __func__, name, size);
328
329 if (size > ORANGEFS_MAX_XATTR_VALUELEN)
330 return -EINVAL;
331 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
332 return -EINVAL;
333
334 internal_flag = convert_to_internal_xattr_flags(flags);
335
336 /* This is equivalent to a removexattr */
337 if (size == 0 && !value) {
338 gossip_debug(GOSSIP_XATTR_DEBUG,
339 "removing xattr (%s)\n",
340 name);
341 return orangefs_inode_removexattr(inode, name, flags);
342 }
343
344 gossip_debug(GOSSIP_XATTR_DEBUG,
345 "setxattr on inode %pU, name %s\n",
346 get_khandle_from_ino(inode),
347 name);
348
349 down_write(&orangefs_inode->xattr_sem);
350 new_op = op_alloc(ORANGEFS_VFS_OP_SETXATTR);
351 if (!new_op)
352 goto out_unlock;
353
354
355 new_op->upcall.req.setxattr.refn = orangefs_inode->refn;
356 new_op->upcall.req.setxattr.flags = internal_flag;
357 /*
358 * NOTE: Although keys are meant to be NULL terminated textual
359 * strings, I am going to explicitly pass the length just in
360 * case we change this later on...
361 */
362 strcpy(new_op->upcall.req.setxattr.keyval.key, name);
363 new_op->upcall.req.setxattr.keyval.key_sz = strlen(name) + 1;
364 memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
365 new_op->upcall.req.setxattr.keyval.val_sz = size;
366
367 gossip_debug(GOSSIP_XATTR_DEBUG,
368 "orangefs_inode_setxattr: key %s, key_sz %d "
369 " value size %zd\n",
370 (char *)new_op->upcall.req.setxattr.keyval.key,
371 (int)new_op->upcall.req.setxattr.keyval.key_sz,
372 size);
373
374 ret = service_operation(new_op,
375 "orangefs_inode_setxattr",
376 get_interruptible_flag(inode));
377
378 gossip_debug(GOSSIP_XATTR_DEBUG,
379 "orangefs_inode_setxattr: returning %d\n",
380 ret);
381
382 /* when request is serviced properly, free req op struct */
383 op_release(new_op);
384
385 h = &orangefs_inode->xattr_cache[xattr_key(name)];
386 hlist_for_each_entry_safe(cx, tmp, h, node) {
387 if (!strcmp(cx->key, name)) {
388 hlist_del(&cx->node);
389 kfree(cx);
390 break;
391 }
392 }
393
394 out_unlock:
395 up_write(&orangefs_inode->xattr_sem);
396 return ret;
397 }
398
399 /*
400 * Tries to get a specified object's keys into a user-specified buffer of a
401 * given size. Note that like the previous instances of xattr routines, this
402 * also allows you to pass in a NULL pointer and 0 size to probe the size for
403 * subsequent memory allocations. Thus our return value is always the size of
404 * all the keys unless there were errors in fetching the keys!
405 */
orangefs_listxattr(struct dentry * dentry,char * buffer,size_t size)406 ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size)
407 {
408 struct inode *inode = dentry->d_inode;
409 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
410 struct orangefs_kernel_op_s *new_op;
411 __u64 token = ORANGEFS_ITERATE_START;
412 ssize_t ret = -ENOMEM;
413 ssize_t total = 0;
414 int count_keys = 0;
415 int key_size;
416 int i = 0;
417 int returned_count = 0;
418
419 if (size > 0 && !buffer) {
420 gossip_err("%s: bogus NULL pointers\n", __func__);
421 return -EINVAL;
422 }
423
424 down_read(&orangefs_inode->xattr_sem);
425 new_op = op_alloc(ORANGEFS_VFS_OP_LISTXATTR);
426 if (!new_op)
427 goto out_unlock;
428
429 if (buffer && size > 0)
430 memset(buffer, 0, size);
431
432 try_again:
433 key_size = 0;
434 new_op->upcall.req.listxattr.refn = orangefs_inode->refn;
435 new_op->upcall.req.listxattr.token = token;
436 new_op->upcall.req.listxattr.requested_count =
437 (size == 0) ? 0 : ORANGEFS_MAX_XATTR_LISTLEN;
438 ret = service_operation(new_op, __func__,
439 get_interruptible_flag(inode));
440 if (ret != 0)
441 goto done;
442
443 if (size == 0) {
444 /*
445 * This is a bit of a big upper limit, but I did not want to
446 * spend too much time getting this correct, since users end
447 * up allocating memory rather than us...
448 */
449 total = new_op->downcall.resp.listxattr.returned_count *
450 ORANGEFS_MAX_XATTR_NAMELEN;
451 goto done;
452 }
453
454 returned_count = new_op->downcall.resp.listxattr.returned_count;
455 if (returned_count < 0 ||
456 returned_count > ORANGEFS_MAX_XATTR_LISTLEN) {
457 gossip_err("%s: impossible value for returned_count:%d:\n",
458 __func__,
459 returned_count);
460 ret = -EIO;
461 goto done;
462 }
463
464 /*
465 * Check to see how much can be fit in the buffer. Fit only whole keys.
466 */
467 for (i = 0; i < returned_count; i++) {
468 if (new_op->downcall.resp.listxattr.lengths[i] < 0 ||
469 new_op->downcall.resp.listxattr.lengths[i] >
470 ORANGEFS_MAX_XATTR_NAMELEN) {
471 gossip_err("%s: impossible value for lengths[%d]\n",
472 __func__,
473 new_op->downcall.resp.listxattr.lengths[i]);
474 ret = -EIO;
475 goto done;
476 }
477 if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
478 goto done;
479
480 /*
481 * Since many dumb programs try to setxattr() on our reserved
482 * xattrs this is a feeble attempt at defeating those by not
483 * listing them in the output of listxattr.. sigh
484 */
485 if (is_reserved_key(new_op->downcall.resp.listxattr.key +
486 key_size,
487 new_op->downcall.resp.
488 listxattr.lengths[i])) {
489 gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
490 i, new_op->downcall.resp.listxattr.key +
491 key_size);
492 memcpy(buffer + total,
493 new_op->downcall.resp.listxattr.key + key_size,
494 new_op->downcall.resp.listxattr.lengths[i]);
495 total += new_op->downcall.resp.listxattr.lengths[i];
496 count_keys++;
497 } else {
498 gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
499 i, new_op->downcall.resp.listxattr.key +
500 key_size);
501 }
502 key_size += new_op->downcall.resp.listxattr.lengths[i];
503 }
504
505 /*
506 * Since the buffer was large enough, we might have to continue
507 * fetching more keys!
508 */
509 token = new_op->downcall.resp.listxattr.token;
510 if (token != ORANGEFS_ITERATE_END)
511 goto try_again;
512
513 done:
514 gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
515 " [size of buffer %ld] (filled in %d keys)\n",
516 __func__,
517 ret ? (int)ret : (int)total,
518 (long)size,
519 count_keys);
520 op_release(new_op);
521 if (ret == 0)
522 ret = total;
523 out_unlock:
524 up_read(&orangefs_inode->xattr_sem);
525 return ret;
526 }
527
orangefs_xattr_set_default(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * unused,struct inode * inode,const char * name,const void * buffer,size_t size,int flags)528 static int orangefs_xattr_set_default(const struct xattr_handler *handler,
529 struct user_namespace *mnt_userns,
530 struct dentry *unused,
531 struct inode *inode,
532 const char *name,
533 const void *buffer,
534 size_t size,
535 int flags)
536 {
537 return orangefs_inode_setxattr(inode, name, buffer, size, flags);
538 }
539
orangefs_xattr_get_default(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * buffer,size_t size)540 static int orangefs_xattr_get_default(const struct xattr_handler *handler,
541 struct dentry *unused,
542 struct inode *inode,
543 const char *name,
544 void *buffer,
545 size_t size)
546 {
547 return orangefs_inode_getxattr(inode, name, buffer, size);
548
549 }
550
551 static const struct xattr_handler orangefs_xattr_default_handler = {
552 .prefix = "", /* match any name => handlers called with full name */
553 .get = orangefs_xattr_get_default,
554 .set = orangefs_xattr_set_default,
555 };
556
557 const struct xattr_handler *orangefs_xattr_handlers[] = {
558 &posix_acl_access_xattr_handler,
559 &posix_acl_default_xattr_handler,
560 &orangefs_xattr_default_handler,
561 NULL
562 };
563