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