fs: out of bounds on stack in iov_iter_advance
[deliverable/linux.git] / fs / orangefs / xattr.c
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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 */
29static 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
38static 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 */
62ssize_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 }
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80 if ((strlen(name) + strlen(prefix)) >= PVFS_MAX_XATTR_NAMELEN) {
81 gossip_err("Invalid key length (%d)\n",
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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
163out_release_op:
164 op_release(new_op);
165out_unlock:
166 up_read(&pvfs2_inode->xattr_sem);
167 return ret;
168}
169
170static 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);
219out_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 */
230int 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);
327out_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 */
339ssize_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
369try_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
435done:
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;
445out_unlock:
446 up_read(&pvfs2_inode->xattr_sem);
447 return ret;
448}
449
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AV
450static 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)
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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
465static 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)
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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
479static 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)
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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
494static 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)
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499{
500 return pvfs2_inode_getxattr(dentry->d_inode,
501 PVFS2_XATTR_NAME_TRUSTED_PREFIX,
502 name,
503 buffer,
504 size);
505}
506
507static 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
513static 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
524const 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};
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